Re: [PATCH 5/6] mfd: cros_ec_dev: Check communication with ec at resume

From: Gwendal Grignou
Date: Wed Feb 21 2018 - 21:20:31 EST


On Mon, Feb 19, 2018 at 2:41 PM, Enric Balletbo i Serra
<enric.balletbo@xxxxxxxxxxxxx> wrote:
> From: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
This patch is not needed anymore. It was added to
>
> Send dummy command to EC at resume time, wait for status.
> If EC loses that command and return a status for the
> pre-suspend command, we will not interpret that status as an
> answer for an important command.
>
> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Hold on for this commit. We have only used it in 3.14 kernels. It
looks like the issue has been addressed by a more elegant solution at
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/0225a9de5971b99770344c04e0eba5b35ca68f71
> ---
> drivers/mfd/cros_ec_dev.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index fc98e0564061..c901839317ae 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -553,6 +553,16 @@ static __maybe_unused int ec_device_suspend(struct device *dev)
> static __maybe_unused int ec_device_resume(struct device *dev)
> {
> struct cros_ec_dev *ec = dev_get_drvdata(dev);
> + char msg[sizeof(struct ec_response_get_version) +
> + sizeof(CROS_EC_DEV_VERSION)];
> + int ret;
> +
> + /* Be sure the communication with the EC is reestablished */
> + ret = ec_get_version(ec, msg, sizeof(msg));
> + if (ret < 0) {
> + dev_err(ec->ec_dev->dev, "No EC response at resume: %d\n", ret);
> + return 0;
Besides, that looks wrong, we should try to resume the lightbar.
> + }
>
> lb_resume(ec);
>
> --
> 2.16.1
>