Hi John,
On 12/5/2023 10:10 AM, John Harrison wrote:
On 12/5/2023 00:52, Nirmoy Das wrote:
gen8_engine_reset_prepare() can fail when HW fails to set
RESET_CTL_READY_TO_RESET bit. In some cases this is not fatal
error as driver will retry.
Convert the log to a trace log for debugging without triggering
unnecessary concerns in CI or for end-users during non-fatal scenarios.
I strongly disagree with this change. The hardware spec for the
RESET_CTL and GDRST registers are that they will self clear within a
matter of microseconds. If something is so badly wrong with the
hardware that it can't even manage to reset
This message is for reset readiness poll timeout not that the reset is
failed which doesn't sound so serious if the subsequent attempt managed
reset the engine.
I couldn't get enough details when this can happen that HW takes very
long time to set the readiness bit.
then that is something that very much warrants more than a completely
silent trace event. It most certainly should be flagged as a failure
in CI.
Just because the driver will retry does not mean that this is not a
serious error. And if the first attempt failed, why would a subsequent
attempt succeed?
The patch is not ignoring the failure. If the subsequent attempt fails
then driver load will fail or it will be wedged if that happens after
driver load.
Escalating to FLR may have more success, but that is not something
that i915 currently does.
Do we still need to do FLR if a subsequent engine reset failure ?
Regards,
Nirmoy
John.
v2: Improve commit message(Tvrtko)
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: John Harrison <John.C.Harrison@xxxxxxxxx>
Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5591
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_reset.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c
b/drivers/gpu/drm/i915/gt/intel_reset.c
index d5ed904f355d..e6fbc6202c80 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -593,10 +593,10 @@ static int gen8_engine_reset_prepare(struct
intel_engine_cs *engine)
ret = __intel_wait_for_register_fw(uncore, reg, mask, ack,
700, 0, NULL);
if (ret)
- gt_err(engine->gt,
- "%s reset request timed out: {request: %08x,
RESET_CTL: %08x}\n",
- engine->name, request,
- intel_uncore_read_fw(uncore, reg));
+ GT_TRACE(engine->gt,
+ "%s reset request timed out: {request: %08x, RESET_CTL:
%08x}\n",
+ engine->name, request,
+ intel_uncore_read_fw(uncore, reg));
return ret;
}
