On Tuesday 21 October 2014 06:27:23 Guenter Roeck wrote: > On 10/20/2014 09:46 AM, Pali Rohár wrote: > > Ok, I will describe my problem. Guenter, maybe you can find > > another solution/fix for it. > > > > Calling i8k_get_temp(3) on my laptop without > > I8K_TEMPERATURE_BUG always returns value 193 (which is > > above I8K_MAX_TEMP). > > > > When I8K_TEMPERATURE_BUG is enabled (by default) then > > i8k_get_temp(3) returns value from prev[3] and store new > > value I8K_TEMPERATURE_BUG to prev[3]. Value in prev[3] is > > initialized to 0. > > > > What I want to achieve is: when i8k_get_temp() for > > particular sensor id always returns invalid value (> > > I8K_MAX_TEMP) then we should totally ignore sensor with > > that id and do not export it via hwmon. > > > > My solution is: initialize prev[id] to I8K_MAX_TEMP, so on > > invalid data first call to i8k_get_temp(id) returns > > I8K_MAX_TEMP. Then in i8k_init_hwmon check if value is < > > I8K_MAX_TEMP and if not ignore sensor id. > > > > Guenter, it is clear now? Are you ok that we should ignore > > sensor if always report value above I8K_MAX_TEMP? If you do > > not like my solution/patch for it, can you specify how > > other can it be fixed? > > I still don't see the point in initializing prev[]. >
Now prev[] is initialized to 0. It means that first call i8k_get_temp() (with sensor id which return value > I8K_MAX_TEMP) returns 0. Second and other calls returns I8K_MAX_TEMP. So point is to return same value for first and other calls. > Yes, I am ok with ignoring sensor values if the reported > temperature is above I8K_MAX_TEMP. I am just not sure if we > should check against I8K_MAX_TEMP or against, say, 192. > Reason is that we do know that the sensor can erroneously > return 0x99 on some systems once in a while. We would not > want to ignore those sensors just because they happen to > report 0x99 during initialization. > > So maybe make it > if (err >= 0 && err < 192) > and add a note before the first if(), explaining that higher > values suggest that there is no sensor attached. > > Thanks, > Guenter > Right, now we need to decide which magic constant to use... And now I found another problem :-) On my laptop i8k_get_temp(3) not always return value 193. It is only when AMD graphics card is turned off. When card is on i8k_get_temp(3) returns same value as temperature hwmon part from radeon DRM driver. So it looks like that on my laptop i8k sensor with id 3 reports GPU temperature. When card is turned off radeon driver reports -EINVAL for temperature hwmon sysnode. So now I think i8k could not ignore sensor totally as it can be mapped to some HW which can be dynamically turned on/off (like my graphics card). So what do you think about reporting -EINVAL instead I8K_MAX_TEMP when dell SMM returns value above I8K_MAX_TEMP? -- Pali Rohár pali.ro...@gmail.com
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