From 4bb297113433048169c30a32c1e58b6a1b61b621 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Sun, 30 Jun 2013 22:00:42 +0300 Subject: powerpc/windfarm: Fix overtemperature clearing With pm81/pm91/pm121, when the overtemperature state is entered, and when it remains on after skipped ticks, the driver will try to leave it too soon (immediately on the next tick). This is because the active FAILURE_OVERTEMP state is not visible in "new_failure" variable of the current tick. Furthermore, the driver will keep trying to clear condition in subsequent ticks as FAILURE_OVERTEMP remains set in the "last_failure" variable. These will start to trigger WARNINGS from windfarm core: [ 100.082735] windfarm: Clamping CPU frequency to minimum ! [ 100.108132] windfarm: Overtemp condition detected ! [ 101.952908] windfarm: Overtemp condition cleared ! [...] [ 102.980388] WARNING: at drivers/macintosh/windfarm_core.c:463 [...] [ 103.982227] WARNING: at drivers/macintosh/windfarm_core.c:463 [...] [ 105.030494] WARNING: at drivers/macintosh/windfarm_core.c:463 [...] [ 105.973666] WARNING: at drivers/macintosh/windfarm_core.c:463 [...] [ 106.977913] WARNING: at drivers/macintosh/windfarm_core.c:463 Fix by adding a helper global variable. We leave the overtemp state only after all failure bits have been cleared. I saw this error on iMac G5 iSight (pm121). Also pm81/pm91 are fixed based on the observation that these are almost identical/copy-pasted code. Signed-off-by: Aaro Koskinen Signed-off-by: Benjamin Herrenschmidt --- drivers/macintosh/windfarm_pm121.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/macintosh/windfarm_pm121.c') diff --git a/drivers/macintosh/windfarm_pm121.c b/drivers/macintosh/windfarm_pm121.c index af605e915d41..7fe58b0ae8b4 100644 --- a/drivers/macintosh/windfarm_pm121.c +++ b/drivers/macintosh/windfarm_pm121.c @@ -276,6 +276,7 @@ static const char *loop_names[N_LOOPS] = { static unsigned int pm121_failure_state; static int pm121_readjust, pm121_skipping; +static bool pm121_overtemp; static s32 average_power; struct pm121_correction { @@ -847,6 +848,7 @@ static void pm121_tick(void) if (new_failure & FAILURE_OVERTEMP) { wf_set_overtemp(); pm121_skipping = 2; + pm121_overtemp = true; } /* We only clear the overtemp condition if overtemp is cleared @@ -855,8 +857,10 @@ static void pm121_tick(void) * the control loop levels, but we don't want to keep it clear * here in this case */ - if (new_failure == 0 && last_failure & FAILURE_OVERTEMP) + if (!pm121_failure_state && pm121_overtemp) { wf_clear_overtemp(); + pm121_overtemp = false; + } } -- cgit v1.2.3