From: Matt Roper <matthew.d.roper@xxxxxxxxx> Although we now sanitycheck MMIO access during driver load to make sure the MMIO BAR isn't returning all 0xFFFFFFFF, there have been a few cases where (temporarily?) unreliable MMIO access has happened after GPU resets or power events. We'll often notice this on our next GT register access since forcewake handling will fail; let's change our handling slightly so that when this happens we print a more meaningful message clarifying that the problem is the MMIO access, not forcewake specifically. Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_uncore.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 14ec45e6facfa..8b40a9772df5f 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -178,9 +178,15 @@ static inline void fw_domain_wait_ack_clear(const struct intel_uncore_forcewake_domain *d) { if (wait_ack_clear(d, FORCEWAKE_KERNEL)) { - drm_err(&d->uncore->i915->drm, - "%s: timed out waiting for forcewake ack to clear.\n", - intel_uncore_forcewake_domain_to_str(d->id)); + if (fw_ack(d) == ~0) + drm_err(&d->uncore->i915->drm, + "%s: MMIO unreliable (forcewake register returns 0xFFFFFFFF)!\n", + intel_uncore_forcewake_domain_to_str(d->id)); + else + drm_err(&d->uncore->i915->drm, + "%s: timed out waiting for forcewake ack to clear.\n", + intel_uncore_forcewake_domain_to_str(d->id)); + add_taint_for_CI(d->uncore->i915, TAINT_WARN); /* CI now unreliable */ } } -- 2.39.2