> Roland Dreier wrote:
> > > /* safety net should the EC not support AUTO
> > > * or FULLSPEED mode bits and just ignore them */
> > > if (level & TP_EC_FAN_FULLSPEED)
> > > level |= 7; /* safety min speed 7 */
> > > else if (level & TP_EC_FAN_FULLSPEED)
> > > level |= 4; /* safety min speed 4 */
> > >
> > > Note the duplicate test 'if (level & TP_EC_FAN_FULLSPEED)'. should
> > > this be replaced by
> >
> > Actually I suspect one of the two tests should be against TP_EC_FAN_AUTO
> > (based on the comment).
> >
>
> Thanks Roland, for your info
>
> based on the comments in commit eaa7571b2d1a08873e4bdd8e6db3431df61cd9ad,
> I think this should be modified like below:
>
> ACPI: thinkpad-acpi: add a safety net for TPEC fan control mode
> The Linux ThinkPad community is not positive that all ThinkPads that do
> HFSP EC fan control do implement full-speed and auto modes, some of the
> earlier ones supporting HFSP might not.
>
> If the EC ignores the AUTO or FULL-SPEED bits, it will pay attention to the
> lower three bits that set the fan level. And as thinkpad-acpi was leaving
> these set to zero, it would stop(!) the fan, which is Not A Good Thing.
> So, as a safety net, we now make sure to also set the fan level part of the
> HFSP register to speed 7 for full-speed, and a minimum of speed 4 for auto
> mode.
> --
> second TP_EC_FAN_FULLSPEED should be P_EC_FAN_AUTO
>
>
> Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
> ---
> diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
> index cf56647..3c323fe 100644
> --- a/drivers/misc/thinkpad_acpi.c
> +++ b/drivers/misc/thinkpad_acpi.c
> @@ -4138,7 +4138,7 @@ static int fan_set_level(int level)
> * or FULLSPEED mode bits and just ignore them */
> if (level & TP_EC_FAN_FULLSPEED)
> level |= 7; /* safety min speed 7 */
> - else if (level & TP_EC_FAN_FULLSPEED)
> + else if (level & TP_EC_FAN_AUTO)
> level |= 4; /* safety min speed 4 */
>
> if (!acpi_ec_write(fan_status_offset, level))
>
> --
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