After
commit 2c7d0602c815277f7cb7c932b091288710d8aba7
Author: Imre Deak <imre.deak@xxxxxxxxx>
Date: Mon Dec 5 18:27:37 2016 +0200
drm/i915/gen9: Fix PCODE polling during CDCLK change notification
there is still one report of the CDCLK-change request timing out on a
KBL machine, see the Reference link. On that machine the maximum time
the request took to succeed was 34ms, so increase the timeout to 50ms.
v2:
- Change timeout from 100 to 50 ms to maintain the current 50 ms limit
for atomic waits in the driver. (Chris, Tvrtko)
Reference: https://bugs.freedesktop.org/show_bug.cgi?id=99345
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_pm.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 169c490..e7d4c2a 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -7909,10 +7909,10 @@ static bool skl_pcode_try_request(struct drm_i915_private *dev_priv, u32 mbox,
* @timeout_base_ms: timeout for polling with preemption enabled
*
* Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
- * reports an error or an overall timeout of @timeout_base_ms+10 ms expires.
+ * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
* The request is acknowledged once the PCODE reply dword equals @reply after
* applying @reply_mask. Polling is first attempted with preemption enabled
- * for @timeout_base_ms and if this times out for another 10 ms with
+ * for @timeout_base_ms and if this times out for another 50 ms with
* preemption disabled.
*
* Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
@@ -7948,14 +7948,15 @@ int skl_pcode_request(struct drm_i915_private *dev_priv, u32 mbox, u32 request,
* worst case) _and_ PCODE was busy for some reason even after a
* (queued) request and @timeout_base_ms delay. As a workaround retry
* the poll with preemption disabled to maximize the number of
- * requests. Increase the timeout from @timeout_base_ms to 10ms to
+ * requests. Increase the timeout from @timeout_base_ms to 50ms to
* account for interrupts that could reduce the number of these
- * requests.
+ * requests, and for any quirks of the PCODE firmware that delays
+ * the request completion.
*/
DRM_DEBUG_KMS("PCODE timeout, retrying with preemption disabled\n");
WARN_ON_ONCE(timeout_base_ms > 3);
preempt_disable();
- ret = wait_for_atomic(COND, 10);
+ ret = wait_for_atomic(COND, 50);
preempt_enable();
out:
--
2.5.0