From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 4 May 2020 04:48:42 +0000 (+0100)
Subject: drm/i915: Allow some leniency in PCU reads
X-Git-Tag: block-5.8-2020-06-11~21^2~7^2~85
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=378974f7f9754acfd5630327917c6b813495f1a9;p=linux-block.git

drm/i915: Allow some leniency in PCU reads

Extend the timeout for pcode reads to 20ms as they should not be
performed along critical paths, and succeeding after a short delay is
better than failing entirely.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/1800
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200504044903.7626-1-chris@chris-wilson.co.uk
---

diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index 14daf6af6854..d5129c1dd452 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -429,7 +429,7 @@ int sandybridge_pcode_read(struct drm_i915_private *i915, u32 mbox,
 
 	mutex_lock(&i915->sb_lock);
 	err = __sandybridge_pcode_rw(i915, mbox, val, val1,
-				     500, 0,
+				     500, 20,
 				     true);
 	mutex_unlock(&i915->sb_lock);