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authorLiguang Zhang <zhangliguang@linux.alibaba.com>2021-02-25 17:26:31 +0300
committerWolfram Sang <wsa@kernel.org>2021-02-26 13:26:09 +0300
commitf53f15ba5a852171eccf940b22530152450a045c (patch)
treed32ef2df5c40be9eef99d2397094d080fb9ba252 /drivers/i2c
parenta1858ce0cfe31368b23ba55794e409fb57ced4a4 (diff)
downloadlinux-f53f15ba5a852171eccf940b22530152450a045c.tar.xz
i2c: designware: Get right data length
IC_DATA_CMD[11] indicates the first data byte received after the address phase for receive transfer in Master receiver or Slave receiver mode, this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the data to be transmitted or received on the I2C bus, so we should use the lower 8 bits to get the real data length. Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-designware-core.h2
-rw-r--r--drivers/i2c/busses/i2c-designware-master.c2
2 files changed, 3 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 85307cfa7109..5392b82f68a4 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -38,6 +38,8 @@
#define DW_IC_CON_TX_EMPTY_CTRL BIT(8)
#define DW_IC_CON_RX_FIFO_FULL_HLD_CTRL BIT(9)
+#define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
+
/*
* Registers offset
*/
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index d6425ad6e6a3..dd27b9dbe931 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN &&
- tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
+ (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
len = i2c_dw_recv_len(dev, tmp);
}
*buf++ = tmp;