From f45d50ede6f9e6d76a218e6ed06cc352acad466f Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:39 +0200 Subject: HID: ft260: ft260_xfer_status routine cleanup After clarifying with FTDI's support, it turned out that the error condition (bit 1) in byte 1 of the i2c status HID report is a status bit reflecting all error conditions. When bits 2, 3, or 4 are raised to 1, bit 1 is set to 1 also. Since the ft260_xfer_status routine tests the error condition bit and exits in the case of an error, the program flow never reaches the conditional expressions for 2, 3, and 4 bits when any of them indicates an error state. Though these expressions are never evaluated to true, they are checked several times per IO, increasing the ft260_xfer_status polling cycle duration. The patch removes the conditional expressions for 2, 3, and 4 bits in byte 1 of the i2c status HID report. Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 79505c64dbfe..a35201d68b15 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -313,27 +313,17 @@ static int ft260_xfer_status(struct ft260_device *dev) if (report.bus_status & FT260_I2C_STATUS_CTRL_BUSY) return -EAGAIN; - if (report.bus_status & FT260_I2C_STATUS_BUS_BUSY) - return -EBUSY; - - if (report.bus_status & FT260_I2C_STATUS_ERROR) + /* + * The error condition (bit 1) is a status bit reflecting any + * error conditions. When any of the bits 2, 3, or 4 are raised + * to 1, bit 1 is also set to 1. + */ + if (report.bus_status & FT260_I2C_STATUS_ERROR) { + hid_err(hdev, "i2c bus error: %#02x\n", report.bus_status); return -EIO; + } - ret = -EIO; - - if (report.bus_status & FT260_I2C_STATUS_ADDR_NO_ACK) - ft260_dbg("unacknowledged address\n"); - - if (report.bus_status & FT260_I2C_STATUS_DATA_NO_ACK) - ft260_dbg("unacknowledged data\n"); - - if (report.bus_status & FT260_I2C_STATUS_ARBITR_LOST) - ft260_dbg("arbitration loss\n"); - - if (report.bus_status & FT260_I2C_STATUS_CTRL_IDLE) - ret = 0; - - return ret; + return 0; } static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, @@ -376,7 +366,7 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, break; } while (--try); - if (ret == 0 || ret == -EBUSY) + if (ret == 0) return 0; ft260_i2c_reset(hdev); -- cgit v1.2.3 From 6fca5e3f5574ca1bd5bade5737848c816f924c6a Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:40 +0200 Subject: HID: ft260: improve i2c write performance The patch improves the I2C write performance by 20 - 30 percent by revising the sleep time in the ft260_hid_output_report_check_status() in the following ways: 1. Reduce the wait time and start to poll earlier. Sending a large amount of data at a low I2C clock rate saturates the internal FT260 buffer and causes hiccups in status readiness, as shown below in the log fragment. Aligning the status check wait time to the worst case significantly reduces the write performance. [Oct22 10:28] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.005296] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.013460] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003244] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000190] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.015324] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003491] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000202] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.016047] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.002768] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000150] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011389] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003467] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000191] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000172] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000131] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000241] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000233] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000190] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000196] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011314] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 [ +0.003334] ft260_hid_output_report_check_status: wait 1920 usec, len 38 [ +0.000227] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000204] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000198] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000147] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.011060] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0 Before: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 40510 80 256 8 32 After: $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 52584 80 256 8 32 2. Do not sleep if the estimated I2C transfer time is below 2 ms since the first xfer status query frequently takes around 1.5 ms, and the following status queries take about 200us on average. So we usually return from the routine after the first 1 - 3 status checks. [Oct22 11:14] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.004270] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.013889] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.000856] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000138] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.013352] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.001501] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000177] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.014477] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 [ +0.001377] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000233] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000191] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.013197] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0 Before: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 28826 73 256 16 16 After: $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 45138 73 256 16 16 Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index a35201d68b15..44106cadd746 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -345,7 +345,7 @@ static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, static int ft260_hid_output_report_check_status(struct ft260_device *dev, u8 *data, int len) { - int ret, usec, try = 3; + int ret, usec, try = 100; struct hid_device *hdev = dev->hdev; ret = ft260_hid_output_report(hdev, data, len); @@ -356,10 +356,14 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, return ret; } - /* transfer time = 1 / clock(KHz) * 10 bits * bytes */ - usec = 10000 / dev->clock * len; - usleep_range(usec, usec + 100); - ft260_dbg("wait %d usec, len %d\n", usec, len); + /* transfer time = 1 / clock(KHz) * 9 bits * bytes */ + usec = len * 9000 / dev->clock; + if (usec > 2000) { + usec -= 1500; + usleep_range(usec, usec + 100); + ft260_dbg("wait %d usec, len %d\n", usec, len); + } + do { ret = ft260_xfer_status(dev); if (ret != -EAGAIN) -- cgit v1.2.3 From 1edfae51d5763439b2c89c9419c377f9c0da354d Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:41 +0200 Subject: HID: ft260: support i2c writes larger than HID report size To support longer than one HID report size write, the driver splits a single i2c message data payload into multiple i2c messages of HID report size. However, it does not replicate the offset bytes within the EEPROM chip in every consequent HID report because it is not and should not be aware of the EEPROM type. It breaks the i2c write message integrity and causes the EEPROM device not to acknowledge the second HID report keeping the i2c bus busy until the ft260 controller reports failure. This patch preserves the i2c write message integrity by manipulating the i2c flag bits across multiple HID reports to be seen by the EEPROM device as a single i2c write transfer. Before: $ sudo ./i2cperf -f 2 -o 2 -s 64 -r 0-0xff 13 0x51 -S Error: Sending messages failed: Input/output error [ +3.667741] ft260_i2c_write: rep 0xde addr 0x51 off 0 len 60 d[0] 0x0 [ +0.007330] ft260_hid_output_report_check_status: wait 6400 usec, len 64 [ +0.000203] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_write: rep 0xd1 addr 0x51 off 60 len 6 d[0] 0x0 [ +0.002337] ft260_hid_output_report_check_status: wait 1000 usec, len 10 [ +0.000157] ft260_xfer_status: bus_status 0x2e, clock 100 [ +0.000241] ft260_i2c_reset: done [ +0.000003] ft260_i2c_write: failed to start transfer, ret -5 After: $ sudo ./i2cperf -f 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S Fill block with increment via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 71260 86 256 2 128 Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 44106cadd746..cec83f69ebdc 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -378,41 +378,46 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, } static int ft260_i2c_write(struct ft260_device *dev, u8 addr, u8 *data, - int data_len, u8 flag) + int len, u8 flag) { - int len, ret, idx = 0; + int ret, wr_len, idx = 0; struct hid_device *hdev = dev->hdev; struct ft260_i2c_write_request_report *rep = (struct ft260_i2c_write_request_report *)dev->write_buf; + rep->flag = FT260_FLAG_START; + do { - if (data_len <= FT260_WR_DATA_MAX) - len = data_len; - else - len = FT260_WR_DATA_MAX; + if (len <= FT260_WR_DATA_MAX) { + wr_len = len; + if (flag == FT260_FLAG_START_STOP) + rep->flag |= FT260_FLAG_STOP; + } else { + wr_len = FT260_WR_DATA_MAX; + } - rep->report = FT260_I2C_DATA_REPORT_ID(len); + rep->report = FT260_I2C_DATA_REPORT_ID(wr_len); rep->address = addr; - rep->length = len; - rep->flag = flag; + rep->length = wr_len; - memcpy(rep->data, &data[idx], len); + memcpy(rep->data, &data[idx], wr_len); - ft260_dbg("rep %#02x addr %#02x off %d len %d d[0] %#02x\n", - rep->report, addr, idx, len, data[0]); + ft260_dbg("rep %#02x addr %#02x off %d len %d wlen %d flag %#x d[0] %#02x\n", + rep->report, addr, idx, len, wr_len, + rep->flag, data[0]); ret = ft260_hid_output_report_check_status(dev, (u8 *)rep, - len + 4); + wr_len + 4); if (ret < 0) { - hid_err(hdev, "%s: failed to start transfer, ret %d\n", - __func__, ret); + hid_err(hdev, "%s: failed with %d\n", __func__, ret); return ret; } - data_len -= len; - idx += len; + len -= wr_len; + idx += wr_len; + rep->flag = 0; - } while (data_len > 0); + } while (len > 0); return 0; } -- cgit v1.2.3 From 0acb869f40ecc328ed87e389cc08122e3aeba1a8 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:42 +0200 Subject: HID: ft260: support i2c reads greater than HID report size A random i2c read operation in EEPROM devices is implemented as a dummy write operation, followed by a current address read operation. The dummy write operation is used to load the target byte or word address (a.k.a offset) into the offset counter, from which the subsequent read operation then reads. To support longer than one HID report size random read, the ft260 driver issues multiple pairs of i2c write offset + read data transactions of HID report size so that the EEPROM device sees many i2c random read requests from different offsets. Two issues with the current implementation: - This approach suffers from extra overhead caused by writing offset requests. - Necessity to handle offset per HID report in big-endian representation as EEPROM devices expect. The current implementation does not do it and correctly handles the reads up to 60 bytes only. This patch addresses both issues by implementing more efficient approach. It issues a single i2c read request of up to the EEPROM page size and then waits for the data to arrive in multiple HID reports. For example, to read the 256 bytes from a 24LC512 chip, which has 128 bytes page size, the old method performs six ft260_i2c_write_read transactions while the new - two only. Before: $ sudo ./i2cperf -d 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S Read block via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 40803 85 256 2 128 Kernel log of a single 128 bytes read request: [ +2.376308] ft260_i2c_write_read: read_off 0x0 left_len 128 len 60 [ +0.000002] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.000707] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000173] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 [ +0.008660] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000156] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000001] ft260_i2c_write_read: read_off 0x3c left_len 68 len 60 [ +0.000001] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x3c [ +0.001034] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000191] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 [ +0.008614] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000203] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000001] ft260_i2c_write_read: read_off 0x78 left_len 8 len 8 [ +0.000001] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x78 [ +0.000987] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000192] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 8 [ +0.002614] ft260_raw_event: i2c resp: rep 0xd1 len 8 [ +0.000200] ft260_xfer_status: bus_status 0x20, clock 100 After: $ sudo ./i2cperf -d 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S Read block via i2ctransfer by chunks ------------------------------------------------------------------- data rate(bps) efficiency(%) data size(B) total IOs IO size(B) ------------------------------------------------------------------- 43990 85 256 2 128 Kernel log of a single 128 bytes read request: [ +1.464346] ft260_i2c_write_read: off 0x0 rlen 128 wlen 2 [ +0.000002] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.001653] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000188] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 128 rlen 60 flag 0x3 [ +0.008609] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000157] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 68 rlen 60 flag 0x0 [ +0.008840] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000203] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 8 rlen 8 flag 0x4 [ +0.002794] ft260_raw_event: i2c resp: rep 0xd1 len 8 [ +0.000201] ft260_xfer_status: bus_status 0x20, clock 100 Signed-off-by: Michael Zaidman Tested-by: Guillaume Champagne Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 127 +++++++++++++++++++++++++----------------------- 1 file changed, 66 insertions(+), 61 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index cec83f69ebdc..a354089bb747 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -456,49 +456,62 @@ static int ft260_smbus_write(struct ft260_device *dev, u8 addr, u8 cmd, static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, u16 len, u8 flag) { + u16 rd_len; + int timeout, ret; struct ft260_i2c_read_request_report rep; struct hid_device *hdev = dev->hdev; - int timeout; - int ret; - if (len > FT260_RD_DATA_MAX) { - hid_err(hdev, "%s: unsupported rd len: %d\n", __func__, len); - return -EINVAL; - } + if ((flag & FT260_FLAG_START_REPEATED) == FT260_FLAG_START_REPEATED) + flag = FT260_FLAG_START_REPEATED; + else + flag = FT260_FLAG_START; + do { + if (len <= FT260_RD_DATA_MAX) { + rd_len = len; + flag |= FT260_FLAG_STOP; + } else { + rd_len = FT260_RD_DATA_MAX; + } - dev->read_idx = 0; - dev->read_buf = data; - dev->read_len = len; + dev->read_idx = 0; + dev->read_buf = data; + dev->read_len = rd_len; - rep.report = FT260_I2C_READ_REQ; - rep.length = cpu_to_le16(len); - rep.address = addr; - rep.flag = flag; + rep.report = FT260_I2C_READ_REQ; + rep.length = cpu_to_le16(rd_len); + rep.address = addr; + rep.flag = flag; - ft260_dbg("rep %#02x addr %#02x len %d\n", rep.report, rep.address, - rep.length); + ft260_dbg("rep %#02x addr %#02x len %d rlen %d flag %#x\n", + rep.report, rep.address, len, rd_len, flag); - reinit_completion(&dev->wait); + reinit_completion(&dev->wait); - ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep)); - if (ret < 0) { - hid_err(hdev, "%s: failed to start transaction, ret %d\n", - __func__, ret); - return ret; - } + ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep)); + if (ret < 0) { + hid_err(hdev, "%s: failed with %d\n", __func__, ret); + return ret; + } - timeout = msecs_to_jiffies(5000); - if (!wait_for_completion_timeout(&dev->wait, timeout)) { - ft260_i2c_reset(hdev); - return -ETIMEDOUT; - } + timeout = msecs_to_jiffies(5000); + if (!wait_for_completion_timeout(&dev->wait, timeout)) { + ft260_i2c_reset(hdev); + return -ETIMEDOUT; + } - ret = ft260_xfer_status(dev); - if (ret == 0) - return 0; + ret = ft260_xfer_status(dev); + if (ret < 0) { + ft260_i2c_reset(hdev); + return -EIO; + } - ft260_i2c_reset(hdev); - return -EIO; + len -= rd_len; + data += rd_len; + flag = 0; + + } while (len > 0); + + return 0; } /* @@ -509,45 +522,37 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, */ static int ft260_i2c_write_read(struct ft260_device *dev, struct i2c_msg *msgs) { - int len, ret; - u16 left_len = msgs[1].len; - u8 *read_buf = msgs[1].buf; + int ret; + int wr_len = msgs[0].len; + int rd_len = msgs[1].len; + struct hid_device *hdev = dev->hdev; u8 addr = msgs[0].addr; u16 read_off = 0; - struct hid_device *hdev = dev->hdev; - if (msgs[0].len > 2) { - hid_err(hdev, "%s: unsupported wr len: %d\n", __func__, - msgs[0].len); + if (wr_len > 2) { + hid_err(hdev, "%s: invalid wr_len: %d\n", __func__, wr_len); return -EOPNOTSUPP; } - memcpy(&read_off, msgs[0].buf, msgs[0].len); - - do { - if (left_len <= FT260_RD_DATA_MAX) - len = left_len; + if (ft260_debug) { + if (wr_len == 2) + read_off = be16_to_cpu(*(u16 *)msgs[0].buf); else - len = FT260_RD_DATA_MAX; + read_off = *msgs[0].buf; - ft260_dbg("read_off %#x left_len %d len %d\n", read_off, - left_len, len); - - ret = ft260_i2c_write(dev, addr, (u8 *)&read_off, msgs[0].len, - FT260_FLAG_START); - if (ret < 0) - return ret; - - ret = ft260_i2c_read(dev, addr, read_buf, len, - FT260_FLAG_START_STOP); - if (ret < 0) - return ret; + pr_info("%s: off %#x rlen %d wlen %d\n", __func__, + read_off, rd_len, wr_len); + } - left_len -= len; - read_buf += len; - read_off += len; + ret = ft260_i2c_write(dev, addr, msgs[0].buf, wr_len, + FT260_FLAG_START); + if (ret < 0) + return ret; - } while (left_len > 0); + ret = ft260_i2c_read(dev, addr, msgs[1].buf, rd_len, + FT260_FLAG_START_STOP_REPEATED); + if (ret < 0) + return ret; return 0; } -- cgit v1.2.3 From 54410c14800ad652c77e5c6fc5c17baad6e42cb6 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:43 +0200 Subject: HID: ft260: improve i2c large reads performance The patch increases the read buffer size to 180 bytes. It reduces the number of ft260_i2c_read() calls by three, improving the big reads performance. $ sudo i2ctransfer -y -f 13 w2@0x51 0x0 0x0 r180 Before: [ +4.071878] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.001097] ft260_xfer_status: bus_status 0x41, clock 100 [ +0.000175] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000004] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 60 flag 0x3 [ +0.008579] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000208] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 120 rlen 60 flag 0x0 [ +0.008794] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000181] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000002] ft260_i2c_read: rep 0xc2 addr 0x51 len 60 rlen 60 flag 0x4 [ +0.008817] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000223] ft260_xfer_status: bus_status 0x20, clock 100 After: [ +11.611642] ft260_i2c_write_read: off 0x0 rlen 180 wlen 2 [ +0.000005] ft260_i2c_write: rep 0xd0 addr 0x51 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.008001] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000001] ft260_i2c_read: rep 0xc2 addr 0x51 len 180 rlen 180 flag 0x7 [ +0.008994] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007987] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.007992] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.000206] ft260_xfer_status: bus_status 0x20, clock 100 Suggested-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index a354089bb747..91f9087e49dc 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -30,12 +30,19 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages"); #define FT260_REPORT_MAX_LENGTH (64) #define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4) + /* - * The input report format assigns 62 bytes for the data payload, but ft260 - * returns 60 and 2 in two separate transactions. To minimize transfer time - * in reading chunks mode, set the maximum read payload length to 60 bytes. - */ -#define FT260_RD_DATA_MAX (60) + * The ft260 input report format defines 62 bytes for the data payload, but + * when requested 62 bytes, the controller returns 60 and 2 in separate input + * reports. To achieve better performance with the multi-report read data + * transfers, we set the maximum read payload length to a multiple of 60. + * With a 100 kHz I2C clock, one 240 bytes read takes about 1/27 second, + * which is excessive; On the other hand, some higher layer drivers like at24 + * or optoe limit the i2c reads to 128 bytes. To not block other drivers out + * of I2C for potentially troublesome amounts of time, we select the maximum + * read payload length to be 180 bytes. +*/ +#define FT260_RD_DATA_MAX (180) #define FT260_WR_DATA_MAX (60) /* -- cgit v1.2.3 From 76e76e7993f3d8da484424135a4a8acf7f3cac0b Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:44 +0200 Subject: HID: ft260: do not populate /dev/hidraw device Do not populate the /dev/hidraw on ft260 interfaces when the hid-ft260 driver is loaded. $ sudo insmod hid-ft260.ko $ ls /dev/hidraw* /dev/hidraw0 $ sudo rmmod hid-ft260.ko $ ls /dev/hidraw* /dev/hidraw0 /dev/hidraw1 /dev/hidraw2 Reported-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 91f9087e49dc..8d6d2a19b9ed 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -939,7 +939,7 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) return ret; } - ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); + ret = hid_hw_start(hdev, 0); if (ret) { hid_err(hdev, "failed to start HID HW\n"); return ret; @@ -966,6 +966,10 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) if (ret <= 0) goto err_hid_close; + hid_info(hdev, "USB HID v%x.%02x Device [%s] on %s\n", + hdev->version >> 8, hdev->version & 0xff, hdev->name, + hdev->phys); + hid_set_drvdata(hdev, dev); dev->hdev = hdev; dev->adap.owner = THIS_MODULE; @@ -974,8 +978,7 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) dev->adap.quirks = &ft260_i2c_quirks; dev->adap.dev.parent = &hdev->dev; snprintf(dev->adap.name, sizeof(dev->adap.name), - "FT260 usb-i2c bridge on hidraw%d", - ((struct hidraw *)hdev->hidraw)->minor); + "FT260 usb-i2c bridge"); mutex_init(&dev->lock); init_completion(&dev->wait); -- cgit v1.2.3 From b7121e3c04440cc2af9cabbabb24efd23741294a Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:45 +0200 Subject: HID: ft260: skip unexpected HID input reports The FT260 is not supposed to generate unexpected HID reports. However, in theory, the unsolicited HID Input reports can be issued by a specially crafted malicious USB device masquerading as FT260 when the attacker has physical access to the USB port. In this case, the read_buf pointer points to the final data portion of the previous I2C Read transfer, and the memcpy invoked in the ft260_raw_event() will try copying the content of the unexpected report into the wrong location. This commit sets the Read buffer pointer to NULL on the I2C Read transaction completion and checks it in the ft260_raw_event() to detect and skip the unsolicited Input report. Reported-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 8d6d2a19b9ed..8b6ebc5228eb 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -464,7 +464,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, u16 len, u8 flag) { u16 rd_len; - int timeout, ret; + int timeout, ret = 0; struct ft260_i2c_read_request_report rep; struct hid_device *hdev = dev->hdev; @@ -480,10 +480,6 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, rd_len = FT260_RD_DATA_MAX; } - dev->read_idx = 0; - dev->read_buf = data; - dev->read_len = rd_len; - rep.report = FT260_I2C_READ_REQ; rep.length = cpu_to_le16(rd_len); rep.address = addr; @@ -494,22 +490,30 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, reinit_completion(&dev->wait); + dev->read_idx = 0; + dev->read_buf = data; + dev->read_len = rd_len; + ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep)); if (ret < 0) { hid_err(hdev, "%s: failed with %d\n", __func__, ret); - return ret; + goto ft260_i2c_read_exit; } timeout = msecs_to_jiffies(5000); if (!wait_for_completion_timeout(&dev->wait, timeout)) { + ret = -ETIMEDOUT; ft260_i2c_reset(hdev); - return -ETIMEDOUT; + goto ft260_i2c_read_exit; } + dev->read_buf = NULL; + ret = ft260_xfer_status(dev); if (ret < 0) { + ret = -EIO; ft260_i2c_reset(hdev); - return -EIO; + goto ft260_i2c_read_exit; } len -= rd_len; @@ -518,7 +522,9 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, } while (len > 0); - return 0; +ft260_i2c_read_exit: + dev->read_buf = NULL; + return ret; } /* @@ -1036,6 +1042,13 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, ft260_dbg("i2c resp: rep %#02x len %d\n", xfer->report, xfer->length); + if ((dev->read_buf == NULL) || + (xfer->length > dev->read_len - dev->read_idx)) { + hid_err(hdev, "unexpected report %#02x, length %d\n", + xfer->report, xfer->length); + return -1; + } + memcpy(&dev->read_buf[dev->read_idx], &xfer->data, xfer->length); dev->read_idx += xfer->length; @@ -1044,10 +1057,9 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, complete(&dev->wait); } else { - hid_err(hdev, "unknown report: %#02x\n", xfer->report); - return 0; + hid_err(hdev, "unhandled report %#02x\n", xfer->report); } - return 1; + return 0; } static struct hid_driver ft260_driver = { -- cgit v1.2.3 From 3b56ff4820cf9d36a770d01769d5d9a6c3b14891 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:46 +0200 Subject: HID: ft260: remove SMBus Quick command support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The i2cdetect uses the SMBus Quick command by default to scan devices on the I2C bus. The FT260 implements an I2C bus controller. The SMBus is derived from I2C, but there are several differences between the specifications of the two buses in the areas of timing, protocols, operation modes, and electrical characteristics. One of the differences is that the I2C devices allow the slave not to ACK its slave address, but SMBus requires it to always ACK it as a mechanism to detect a detachable device’s presence on the bus. Since FT260 is the I2C bus controller, it does not acknowledge the SMBus Quick write command, which sends a single bit to the device at the place of the RD/WR bit. The ft260 driver attempted to mimic the SMBus Quick Write functionality by writing a single byte as the SMBus Byte Write command does. Usually, one byte in the SMBus Quick Write will be fine. However, it may cause problems with devices with a control register at offset 0, like i2c muxes, for example, when scanned with the i2cdetect utility. The i2cdetect with the "-r" option uses the SMBus Read Byte command, which is a reasonable workaround. To prevent the I2C bus from locking at write-only devices (most notably clock chips at address 0x69), use the "-r" option in conjunction with scanning range parameters. This patch removes the SMBus Quick command support. $ sudo i2cdetect -y 13 Warning: Can't use SMBus Quick Write command, will skip some addresses 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: 10: 20: 30: -- -- -- -- -- -- -- -- 40: 50: 50 51 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: 70: $ sudo i2cdetect -y -r 13 0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: 50 51 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- -- Reported-by: Vince Asbridge Reported-by: Stephen Shirron Reported-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 8b6ebc5228eb..d186aa5a8e73 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -630,14 +630,6 @@ static int ft260_smbus_xfer(struct i2c_adapter *adapter, u16 addr, u16 flags, } switch (size) { - case I2C_SMBUS_QUICK: - if (read_write == I2C_SMBUS_READ) - ret = ft260_i2c_read(dev, addr, &data->byte, 0, - FT260_FLAG_START_STOP); - else - ret = ft260_smbus_write(dev, addr, cmd, NULL, 0, - FT260_FLAG_START_STOP); - break; case I2C_SMBUS_BYTE: if (read_write == I2C_SMBUS_READ) ret = ft260_i2c_read(dev, addr, &data->byte, 1, @@ -720,7 +712,7 @@ smbus_exit: static u32 ft260_functionality(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_QUICK | + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_I2C_BLOCK; } -- cgit v1.2.3 From 728b117e7862b1eb05c3aad3b2f087b26453d56a Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:47 +0200 Subject: HID: ft260: missed NACK from big i2c read The FT260 controller does not return NACK when performing a big read (of multiple hid reports size) from a non-existing device or from the device responding with NACK when it is not ready to serve the request. However, it responds correctly with NACK to a read of up to a single hid report size. To overcome this issue, we split the muli-report read request into a read of a single HID report of 60 bytes size and a multi-report read. Big read of 256 bytes with first read of 60 bytes: $ sudo ./i2cperf -d 2 -o 2 -s 256 -r 0-0xff 1 0x50 -S [ +5.633280] ft260_i2c_write_read: off 0x0 rlen 255 wlen 2 [ +0.000006] ft260_i2c_write: rep 0xd0 addr 0x50 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.013205] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000007] ft260_i2c_read: rep 0xc2 addr 0x50 len 255 rlen 60 flag 0x3 [ +0.010932] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.004733] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000006] ft260_i2c_read: rep 0xc2 addr 0x50 len 195 rlen 128 flag 0x0 [ +0.012572] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.005789] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.003189] ft260_raw_event: i2c resp: rep 0xd1 len 8 [ +0.004092] ft260_xfer_status: bus_status 0x40, clock 100 [ +0.000010] ft260_i2c_read: rep 0xc2 addr 0x50 len 67 rlen 67 flag 0x4 [ +0.011688] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.004700] ft260_raw_event: i2c resp: rep 0xd1 len 7 [ +0.004858] ft260_xfer_status: bus_status 0x20, clock 100 Read from non-existing device at address 8. The first 60 read responded with NACK. $ sudo ./i2cperf -d 2 -o 2 -s 256 -r 0-0xff 1 0x8 -S [Oct19 15:37] ft260_i2c_write_read: off 0x0 rlen 255 wlen 2 [ +0.000007] ft260_i2c_write: rep 0xd0 addr 0x8 off 0 len 2 wlen 2 flag 0x2 d[0] 0x0 [ +0.022820] ft260_xfer_status: bus_status 0x20, clock 100 [ +0.000007] ft260_i2c_read: rep 0xc2 addr 0x8 len 255 rlen 60 flag 0x3 [ +0.010658] ft260_raw_event: i2c resp: rep 0xde len 60 [ +0.005965] ft260_xfer_status: bus_status 0x46, clock 100 <-- NACK [ +0.000009] ft260 0003:0403:6030.0004: i2c bus error: 0x46 [ +0.007784] ft260_i2c_reset: done Co-developed-by: Enrik Berkhan Signed-off-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index d186aa5a8e73..40fae81386e3 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -464,6 +464,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, u16 len, u8 flag) { u16 rd_len; + u16 rd_data_max = 60; int timeout, ret = 0; struct ft260_i2c_read_request_report rep; struct hid_device *hdev = dev->hdev; @@ -473,12 +474,13 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, else flag = FT260_FLAG_START; do { - if (len <= FT260_RD_DATA_MAX) { + if (len <= rd_data_max) { rd_len = len; flag |= FT260_FLAG_STOP; } else { - rd_len = FT260_RD_DATA_MAX; + rd_len = rd_data_max; } + rd_data_max = FT260_RD_DATA_MAX; rep.report = FT260_I2C_READ_REQ; rep.length = cpu_to_le16(rd_len); -- cgit v1.2.3 From 4b3da6853a619a952e8caf2e8393264dd42ffa27 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:48 +0200 Subject: HID: ft260: wake up device from power saving mode The FT260 can enter a power saving mode after being idle for longer than 5 seconds. When being woken up from power saving mode by an I2C write request, a possible NACK is not correctly reported by the controller. As a workaround, the driver will issue an I2C status report two times in ft260_xfer_status() after the chip has been idle for more than 5s. Co-developed-by: Enrik Berkhan Signed-off-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 40fae81386e3..ac133980dfe9 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -31,6 +31,8 @@ MODULE_PARM_DESC(debug, "Toggle FT260 debugging messages"); #define FT260_REPORT_MAX_LENGTH (64) #define FT260_I2C_DATA_REPORT_ID(len) (FT260_I2C_REPORT_MIN + (len - 1) / 4) +#define FT260_WAKEUP_NEEDED_AFTER_MS (4800) /* 5s minus 200ms margin */ + /* * The ft260 input report format defines 62 bytes for the data payload, but * when requested 62 bytes, the controller returns 60 and 2 in separate input @@ -237,6 +239,7 @@ struct ft260_device { struct completion wait; struct mutex lock; u8 write_buf[FT260_REPORT_MAX_LENGTH]; + unsigned long need_wakeup_at; u8 *read_buf; u16 read_idx; u16 read_len; @@ -306,6 +309,20 @@ static int ft260_xfer_status(struct ft260_device *dev) struct ft260_get_i2c_status_report report; int ret; + if (time_is_before_jiffies(dev->need_wakeup_at)) { + ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS, + (u8 *)&report, sizeof(report)); + if (unlikely(ret < 0)) { + hid_err(hdev, "failed to retrieve status: %d, no wakeup\n", + ret); + } else { + dev->need_wakeup_at = jiffies + + msecs_to_jiffies(FT260_WAKEUP_NEEDED_AFTER_MS); + ft260_dbg("bus_status %#02x, wakeup\n", + report.bus_status); + } + } + ret = ft260_hid_feature_report_get(hdev, FT260_I2C_STATUS, (u8 *)&report, sizeof(report)); if (unlikely(ret < 0)) { -- cgit v1.2.3 From c2500bdffe5a95fbd0aecdd5be3d2f175ad22f92 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:49 +0200 Subject: HID: ft260: fix a NULL pointer dereference in ft260_i2c_write The zero-length passed into the ft260_i2c_write() triggered the NULL pointer dereference in the debug message on data[0] access. Since the controller does not support a write of zero length, let's not allow it. Before: $ sudo i2ctransfer -y 13 w0@0x51 Killed After: $ sudo i2ctransfer -y 13 w0@0x51 Error: Sending messages failed: Invalid argument Reported-by: Enrik Berkhan Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index ac133980dfe9..b4f180c8750a 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -409,6 +409,9 @@ static int ft260_i2c_write(struct ft260_device *dev, u8 addr, u8 *data, struct ft260_i2c_write_request_report *rep = (struct ft260_i2c_write_request_report *)dev->write_buf; + if (len < 1) + return -EINVAL; + rep->flag = FT260_FLAG_START; do { -- cgit v1.2.3 From 5afac727defa0b2a3dffb2abd5fb5f594b98d217 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:50 +0200 Subject: HID: ft260: missed NACK from busy device When writing into a slow device like an EEPROM chip, the controller may exit the busy state before the device releases the bus. In this case, the ft260_xfer_status returns success before the data transfer completion. The patch fixes it by returning from the ft260_xfer_status() with the "-EAGAIN" on both controller and bus busy status when appropriate. It does not apply to the i2c combined transactions when after the write IO, the controller keeps the bus busy until the read IO and then between reading IOs to ensure an atomic operation. Co-developed-by: Germain Hebert Signed-off-by: Germain Hebert Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index b4f180c8750a..d5b092b85d7f 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -303,7 +303,7 @@ static int ft260_i2c_reset(struct hid_device *hdev) return ret; } -static int ft260_xfer_status(struct ft260_device *dev) +static int ft260_xfer_status(struct ft260_device *dev, u8 bus_busy) { struct hid_device *hdev = dev->hdev; struct ft260_get_i2c_status_report report; @@ -334,7 +334,7 @@ static int ft260_xfer_status(struct ft260_device *dev) ft260_dbg("bus_status %#02x, clock %u\n", report.bus_status, dev->clock); - if (report.bus_status & FT260_I2C_STATUS_CTRL_BUSY) + if (report.bus_status & (FT260_I2C_STATUS_CTRL_BUSY | bus_busy)) return -EAGAIN; /* @@ -369,8 +369,11 @@ static int ft260_hid_output_report(struct hid_device *hdev, u8 *data, static int ft260_hid_output_report_check_status(struct ft260_device *dev, u8 *data, int len) { + u8 bus_busy; int ret, usec, try = 100; struct hid_device *hdev = dev->hdev; + struct ft260_i2c_write_request_report *rep = + (struct ft260_i2c_write_request_report *)data; ret = ft260_hid_output_report(hdev, data, len); if (ret < 0) { @@ -388,8 +391,18 @@ static int ft260_hid_output_report_check_status(struct ft260_device *dev, ft260_dbg("wait %d usec, len %d\n", usec, len); } + /* + * Do not check the busy bit for combined transactions + * since the controller keeps the bus busy between writing + * and reading IOs to ensure an atomic operation. + */ + if (rep->flag == FT260_FLAG_START) + bus_busy = 0; + else + bus_busy = FT260_I2C_STATUS_BUS_BUSY; + do { - ret = ft260_xfer_status(dev); + ret = ft260_xfer_status(dev, bus_busy); if (ret != -EAGAIN) break; } while (--try); @@ -488,6 +501,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, int timeout, ret = 0; struct ft260_i2c_read_request_report rep; struct hid_device *hdev = dev->hdev; + u8 bus_busy = 0; if ((flag & FT260_FLAG_START_REPEATED) == FT260_FLAG_START_REPEATED) flag = FT260_FLAG_START_REPEATED; @@ -531,7 +545,10 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, dev->read_buf = NULL; - ret = ft260_xfer_status(dev); + if (flag & FT260_FLAG_STOP) + bus_busy = FT260_I2C_STATUS_BUS_BUSY; + + ret = ft260_xfer_status(dev, bus_busy); if (ret < 0) { ret = -EIO; ft260_i2c_reset(hdev); @@ -1003,7 +1020,7 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) mutex_init(&dev->lock); init_completion(&dev->wait); - ret = ft260_xfer_status(dev); + ret = ft260_xfer_status(dev, FT260_I2C_STATUS_BUS_BUSY); if (ret) ft260_i2c_reset(hdev); -- cgit v1.2.3 From fb5d783b3c66a0110454a54d2f3bcb7dad4309a1 Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Sat, 5 Nov 2022 23:11:51 +0200 Subject: HID: ft260: fix 'cast to restricted' kernel CI bot warnings Fix 'cast to restricted' sparse warnings reported by kernel test robot in https://lore.kernel.org/all/202211021607.ssjymlKi-lkp@intel.com/ Reported-by: kernel test robot Signed-off-by: Michael Zaidman Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/hid') diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index d5b092b85d7f..333341e80b0e 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -588,7 +588,7 @@ static int ft260_i2c_write_read(struct ft260_device *dev, struct i2c_msg *msgs) if (ft260_debug) { if (wr_len == 2) - read_off = be16_to_cpu(*(u16 *)msgs[0].buf); + read_off = be16_to_cpu(*(__be16 *)msgs[0].buf); else read_off = *msgs[0].buf; @@ -830,7 +830,7 @@ static int ft260_byte_show(struct hid_device *hdev, int id, u8 *cfg, int len, } static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, - u16 *field, u8 *buf) + __le16 *field, u8 *buf) { int ret; @@ -859,9 +859,9 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, #define FT260_I2CST_ATTR_SHOW(name) \ FT260_ATTR_SHOW(name, ft260_get_i2c_status_report, \ - FT260_I2C_STATUS, u16, ft260_word_show) + FT260_I2C_STATUS, __le16, ft260_word_show) -#define FT260_ATTR_STORE(name, reptype, id, req, type, func) \ +#define FT260_ATTR_STORE(name, reptype, id, req, type, ctype, func) \ static ssize_t name##_store(struct device *kdev, \ struct device_attribute *attr, \ const char *buf, size_t count) \ @@ -871,7 +871,7 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, type name; \ int ret; \ \ - if (!func(buf, 10, &name)) { \ + if (!func(buf, 10, (ctype *)&name)) { \ rep.name = name; \ rep.report = id; \ rep.request = req; \ @@ -887,11 +887,11 @@ static int ft260_word_show(struct hid_device *hdev, int id, u8 *cfg, int len, #define FT260_BYTE_ATTR_STORE(name, reptype, req) \ FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \ - u8, kstrtou8) + u8, u8, kstrtou8) #define FT260_WORD_ATTR_STORE(name, reptype, req) \ FT260_ATTR_STORE(name, reptype, FT260_SYSTEM_SETTINGS, req, \ - u16, kstrtou16) + __le16, u16, kstrtou16) FT260_SSTAT_ATTR_SHOW(chip_mode); static DEVICE_ATTR_RO(chip_mode); -- cgit v1.2.3