Messages in this thread | | | Date | Sun, 21 Dec 2014 03:47:15 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH v2 1/2] i8k: Autodetect maximal fan speed and fan RPM multiplier |
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On 12/21/2014 01:13 AM, Pali Rohár wrote: > On Saturday 20 December 2014 19:38:32 Guenter Roeck wrote: >>> + if (fan_mult <= 0) { >> >> Wonder what to do in the < 0 case. It might be better to make >> the variable and the module parameter an unsigned int to >> cover that case, since a negative multiplier doesn't really >> make sense. Same for fan_max. >> > > In some other kernel modules negative value means autodetect. I > think we can do that too. > But 0 already implies autodetect, so that would be redundant.
>>> + /* >>> + * Autodetect fan multiplier for each fan based on >>> nominal rpm + * First set default fan multiplier for each >>> fan + * And if it reports rpm value too high then set >>> multiplier to 1 + * >>> + * Try also setting multiplier from current rpm, but > this >>> will + * work only in case when fan is not turned off. It >>> is better + * then nothing for machines which does not >>> support nominal rpm + * SMM function. >>> + */ >>> + for (fan = 0; fan < ARRAY_SIZE(i8k_fan_mult); ++fan) { >>> + i8k_fan_mult[fan] = I8K_FAN_DEFAULT_MULT; >>> + if (i8k_get_fan_speed(fan) > I8K_FAN_MAX_RPM) { >>> + i8k_fan_mult[fan] = 1; >>> + continue; >>> + } >> >> What if i8k_get_fan_speed(fan) returns an error ? Doesn't that >> imply that the fan does not exist, and that you would not >> need the second loop in the first place ? >> > > See my other email "[PATCH] i8k: Add support for fan labels". DOS > binary check for fan presence by another function. I bet it is > because fan could have same problem as temperature sensors. If > fan is on GPU and GPU is turned off reading fan rpm will fail. > But my laptop (with GPU which can be turned on/off) does not have > GPU fan so this is just my assumption. > Good point.
Guenter
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