Hi, Borislav Petkov writes:
Adding Peter. On Mon, Apr 20, 2015 at 11:21:13AM +0200, Jean Delvare wrote:Commit 178c2490b99f898efc06d1ad75cadc84f13021a6 ("thermal: step_wise: cdev only needs update on a new target state") broke driver acerhdf. That driver abused the step_wise thermal governor until the bang_bang governor was available, and the optimization broke this usage model. Kernels v3.12 to v3.18 are affected. In v3.19 the acerhdf driver was switched to the bang_bang governor and that solved the problem. For kernels v3.12 to v3.17, the bang_bang governor isn't available yet so the easiest fix is to revert the optimization. Signed-off-by: Jean Delvare <jdelv...@suse.de> Reported-by: Dieter Jurzitza (https://bugzilla.opensuse.org/show_bug.cgi?id=925961) Tested-by: Dieter Jurzitza --- Please consider this patch for stable kernel branches from v3.12 to v3.17. If anyone cares about v3.18, I think a better fix would be to backport commit 48c8dd64345ba2a8c41556095c7adacb1c8af7c1 ("acerhdf: Use bang-bang thermal governor") but it's too big for stable, so it's left to distributions. So maybe this fix should make it into v3.18 stable as well - I'll let whoever maintains that branch decide. drivers/thermal/step_wise.c | 3 --- 1 file changed, 3 deletions(-) --- a/drivers/thermal/step_wise.c +++ b/drivers/thermal/step_wise.c @@ -146,9 +146,6 @@ static void thermal_zone_trip_update(str dev_dbg(&instance->cdev->device, "old_target=%d, target=%d\n", old_target, (int)instance->target);- if (old_target == instance->target)- continue; - /* Activate a passive thermal instance */ if (old_target == THERMAL_NO_TARGET && instance->target != THERMAL_NO_TARGET)
Tested-by: Peter Feuerer <pe...@piie.net> thanks. -- kind regards, --peter; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
