Re: [PATCH] dell-smm-hwmon: Cache fan_type() calls and use fan_status() for fan detection

From: Pali RohÃr
Date: Fri May 27 2016 - 05:47:45 EST


On Friday 27 May 2016 10:00:05 Thorsten Leemhuis wrote:
> Pali RohÃr wrote on 26.05.2016 17:51:
> > On Thursday 26 May 2016 17:39:57 Thorsten Leemhuis wrote:
> >> > I need to know if this patch fixes problem on Dell Studio XPS 8000
> >> > and Dell Studio XPS 8100 machines, so we can revert git commits:
> >> > 6220f4ebd7b4 ("hwmon: (dell-smm) Blacklist Dell Studio XPS 8000")
> >> > a4b45b25f18d ("hwmon: (dell-smm) Blacklist Dell Studio XPS 8100")
> >> Just checked: Sorry, that patch did not fix the CPU fan speed issue
> >> on my XPS 8000, so there is afaics no reason to revert 6220f4ebd7b4
> >> :-/
> > Please, can you apply patch "dell-smm-hwmon: In debug mode log duration
> > of SMM calls"
>
> On top of "Cache fan_type() calls and use fan_status() for fan
> detection" or with that patch reverted? I did the latter and
> tested with 4.6 (just mentioning it here in case it matters).

Ideally both.

> > and compile dell-smm-hwmon in debug mode to tell us which
> > SMM call takes too long? This is probably they key for that XPS
> > problems...
>
> [ 5.941037] dell_smm_hwmon: smm(0xfea3 0x0000) = 0x4147 (took 14470 usecs)
> [ 5.941139] dell_smm_hwmon: smm(0x11a3 0x0000) = 0xffff (took 93 usecs)
> [ 5.941236] dell_smm_hwmon: smm(0x11a3 0x0001) = 0xffff (took 93 usecs)
> [ 5.941331] dell_smm_hwmon: smm(0x11a3 0x0002) = 0xffff (took 92 usecs)
> [ 5.941427] dell_smm_hwmon: smm(0x11a3 0x0003) = 0xffff (took 92 usecs)
> [ 5.941526] dell_smm_hwmon: smm(0x03a3 0x0000) = 0x0000 (took 95 usecs)
> [ 5.941625] dell_smm_hwmon: smm(0x03a3 0x0001) = 0x0001 (took 95 usecs)
>
> HTH, CU, knurd

I do not see any long taking SMM call here. Are you really sure that
your machine freeze when loading or using dell-smm-hwmon?

--
Pali RohÃr
pali.rohar@xxxxxxxxx