Re: [PATCH] platform/x86: intel-wmi-thunderbolt: Add dynamic debugging

From: Andy Shevchenko
Date: Wed Sep 26 2018 - 13:02:47 EST


On Wed, Sep 26, 2018 at 7:11 PM Mario Limonciello
<mario.limonciello@xxxxxxxx> wrote:
>
> Some users have been reporting issues with thunderbolt being turned off
> before fully initialized. This is suspected to be caused by userspace
> turning off the Thunderbolt controller using intel-wmi-thunderbolt
> prematurely.
>

> Details are available here:
> https://bugzilla.kernel.org/show_bug.cgi?id=201227
> https://bugzilla.kernel.org/show_bug.cgi?id=199631

BugLink: ... ?
BugLink: ... ?

I can do it myself if you are okay with this format.

The patch itself LGTM.

>
> Userspace has already made some mitigiations for this situation:
> https://github.com/hughsie/fwupd/commit/ef6f1d76983c9b66
> https://github.com/hughsie/fwupd/commit/c07ce5b4889a5384
>
> To allow easier debugging of this situation add output that can be turned
> on with dynamic debugging to better root cause this problem.
>
> Suggested-by: Mika Westerberg <mika.westerberg@xxxxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
> ---
> drivers/platform/x86/intel-wmi-thunderbolt.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/intel-wmi-thunderbolt.c b/drivers/platform/x86/intel-wmi-thunderbolt.c
> index c2257bd..ce5fbf0 100644
> --- a/drivers/platform/x86/intel-wmi-thunderbolt.c
> +++ b/drivers/platform/x86/intel-wmi-thunderbolt.c
> @@ -38,12 +38,16 @@ static ssize_t force_power_store(struct device *dev,
> input.length = sizeof(u8);
> input.pointer = &mode;
> mode = hex_to_bin(buf[0]);
> + dev_dbg(dev, "force_power: storing %#x\n", mode);
> if (mode == 0 || mode == 1) {
> status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
> &input, NULL);
> - if (ACPI_FAILURE(status))
> + if (ACPI_FAILURE(status)) {
> + dev_dbg(dev, "force_power: failed to evaluate ACPI method\n");
> return -ENODEV;
> + }
> } else {
> + dev_dbg(dev, "force_power: unsupported mode\n");
> return -EINVAL;
> }
> return count;
> --
> 2.7.4
>


--
With Best Regards,
Andy Shevchenko