diff options
| author | Javier Martinez Canillas <javier.martinez@collabora.co.uk> | 2015-06-09 14:04:42 +0300 |
|---|---|---|
| committer | Lee Jones <lee.jones@linaro.org> | 2015-06-15 15:18:19 +0300 |
| commit | a841178445bb72a3d566b4e6ab9d19e9b002eb47 (patch) | |
| tree | bdc857e82c9c9e8b49bd5471efa5a954673d58f0 /drivers/platform/chrome/cros_ec_lpc.c | |
| parent | bb03ffb96c72418d06e75c7b74ea62e04c78d322 (diff) | |
| download | linux-a841178445bb72a3d566b4e6ab9d19e9b002eb47.tar.xz | |
mfd: cros_ec: Use a zero-length array for command data
Commit 1b84f2a4cd4a ("mfd: cros_ec: Use fixed size arrays to transfer
data with the EC") modified the struct cros_ec_command fields to not
use pointers for the input and output buffers and use fixed length
arrays instead.
This change was made because the cros_ec ioctl API uses that struct
cros_ec_command to allow user-space to send commands to the EC and
to get data from the EC. So using pointers made the API not 64-bit
safe. Unfortunately this approach was not flexible enough for all
the use-cases since there may be a need to send larger commands
on newer versions of the EC command protocol.
So to avoid to choose a constant length that it may be too big for
most commands and thus wasting memory and CPU cycles on copy from
and to user-space or having a size that is too small for some big
commands, use a zero-length array that is both 64-bit safe and
flexible. The same buffer is used for both output and input data
so the maximum of these values should be used to allocate it.
Suggested-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Diffstat (limited to 'drivers/platform/chrome/cros_ec_lpc.c')
| -rw-r--r-- | drivers/platform/chrome/cros_ec_lpc.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c index 860310513cf0..4c7f0df33bf8 100644 --- a/drivers/platform/chrome/cros_ec_lpc.c +++ b/drivers/platform/chrome/cros_ec_lpc.c @@ -73,8 +73,8 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec, /* Copy data and update checksum */ for (i = 0; i < msg->outsize; i++) { - outb(msg->outdata[i], EC_LPC_ADDR_HOST_PARAM + i); - csum += msg->outdata[i]; + outb(msg->data[i], EC_LPC_ADDR_HOST_PARAM + i); + csum += msg->data[i]; } /* Finalize checksum and write args */ @@ -129,8 +129,8 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec, /* Read response and update checksum */ for (i = 0; i < args.data_size; i++) { - msg->indata[i] = inb(EC_LPC_ADDR_HOST_PARAM + i); - csum += msg->indata[i]; + msg->data[i] = inb(EC_LPC_ADDR_HOST_PARAM + i); + csum += msg->data[i]; } /* Verify checksum */ |