[Intel-gfx] [PATCH] drm/i915: Don't do posting reads on getting forcewake

[Mika Kuoppala]

The checking for ack and also any subsequent mmio access
will serialize with setting the forcewake bit. Drop the
posting read as superfluous.

Note that in the put side we still want to keep the posting read
as it will ensure that the hw sees our forcewake release in a
timely manner and doesn't keep the hw powered up.

Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index be2c7fc..76b60a3 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -131,7 +131,6 @@ fw_domains_get(struct drm_i915_private *dev_priv, enum forcewake_domains fw_doma
 	for_each_fw_domain_mask(d, fw_domains, dev_priv, id) {
 		fw_domain_wait_ack_clear(d);
 		fw_domain_get(d);
-		fw_domain_posting_read(d);
 		fw_domain_wait_ack(d);
 	}
 }
-- 
1.9.1