lkml.org 
[lkml]   [2018]   [Oct]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] mfd: cros-ec: copy the whole event in get_next_event_xfer
From
Date
Hi Emil,

Many thanks to catch this and fix. Some comments below.

You missed to add the v2, please send the next patch with v3 prefix.

On 28/9/18 19:08, Emil Karlson wrote:
> Commit 57e94c8b974db2d83c60e1139c89a70806abbea0 caused cros-ec keyboard events
> be truncated on many chromebooks so that Left and Right keys on Column 12 were
> always 0. Use ret as memcpy len to fix this.
>

That's fine

> drivers/platform/chrome/cros_ec_proto.c:509
> get_next_event_xfer uses ret from cros_ec_cmd_xfer for memcpy for msg->data len
> drivers/platform/chrome/cros_ec_proto.c:445
> cros_ec_cmd_xfer gets ret from send_command
> drivers/platform/chrome/cros_ec_proto.c:93
> send_command gets ret from bus specific xfer_fn
> drivers/mfd/cros_ec_spi.c:598
> cros_ec_cmd_xfer_spi copies len amount to ec_msg->data and returns len as ret
> drivers/mfd/cros_ec_i2c.c:267
> cros_ec_cmd_xfer_i2c copies len amount to ec_msg->data and returns len as ret
>
> so msg->data length is always the same as ret.
>

Instead of describe the different calls involved and the returns. I'd explain
why using ret fixes the issue.

> Fixes: 57e94c8b974d ("mfd: cros-ec: Increase maximum mkbp event size")
> Signed-off-by: Emil Karlson <jekarlson@gmail.com>
> ---
> drivers/platform/chrome/cros_ec_proto.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 398393ab5df8..b6fd4838f60f 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -520,7 +520,7 @@ static int get_next_event_xfer(struct cros_ec_device *ec_dev,
> ret = cros_ec_cmd_xfer(ec_dev, msg);
> if (ret > 0) {
> ec_dev->event_size = ret - 1;
> - memcpy(&ec_dev->event_data, msg->data, ec_dev->event_size);
> + memcpy(&ec_dev->event_data, msg->data, ret);
> }
>
> return ret;
>

After thinking a bit more on this I think that how you fixed this is really
clear. I was wondering if the downstream solution would be better but as is
really late and will be good have this as urgent fix for the coming release I am
happy with it. We can always send follow up patches to sync with the downstream
version if is preferred.

Neil, can you give us your Tested-by to have the make sure this doesn't break
with protocol v1, I don't have such hardware.

Benson, will be really good have this merged in this rc. Are you fine with this
solution?

BTW, you can add my in next version.

Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

\
 
 \ /
  Last update: 2018-10-03 13:01    [W:0.076 / U:0.432 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site