On Thursday, April 2, 2020 12:03:30 PM CEST Zhang Rui wrote: > On Thu, 2020-04-02 at 11:03 +0200, Takashi Iwai wrote: > > On Thu, 02 Apr 2020 09:47:50 +0200, > > Zhang, Rui wrote: > > > > > > CC Viresh. > > > > > > Yes, I've received it. > > > > > > To me, there is not a hard rule that the cooling device max_state > > > must be static. > > > We should be able to detect the max_state change and reset the > > > stats table when necessary. > > > > > > I just finished a prototype patch to do so, and will paste it > > > later. > > > > Great, that sounds like a feasible option, indeed. > > > > > Please try the patch below and see if the problem goes away or not. > > From 7b429674a0e1a6226734c8919b876bb57d946b1d Mon Sep 17 00:00:00 2001 > From: Zhang Rui <rui.zhang@xxxxxxxxx> > Date: Thu, 2 Apr 2020 11:18:44 +0800 > Subject: [RFC PATCH] thermal: update thermal stats table when max cooling > state changed > > The maximum cooling state of a cooling device may be changed at > runtime. Thus the statistics table must be updated to handle the real > maximum cooling states supported. > > This fixes an OOB issue when updating the statistics of the processor > cooling device, because it only supports 1 cooling state before cpufreq > driver loaded. It might also be addressed by adding a ->get_state_count() callback to struct thermal_cooling_device_ops (and fall back to ->get_max_state() if that is NULL) and use that for the stats allocation. If the new callback always returns CPUFREQ_THERMAL_MAX_STEP, the size of the stats table will be sufficient in all cases and acpi_processor_notifier() can update it as needed.
