[PATCH 8/8] drm/i915: Get PM ref before accessing HW register

[John.C.Harrison at Intel.com]

From: Vinay Belgaumkar <vinay.belgaumkar at intel.com>

Seeing these errors when GT is likely in suspend state-
"RPM wakelock ref not held during HW access"

Ensure GT is awake before trying to access HW registers. Avoid
reading the register if that is not the case.

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_rps.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
index 3489f5f0cac1..e1a198bbd135 100644
--- a/drivers/gpu/drm/i915/gt/intel_rps.c
+++ b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -1969,8 +1969,14 @@ u32 intel_rps_read_actual_frequency(struct intel_rps *rps)
 u32 intel_rps_read_punit_req(struct intel_rps *rps)
 {
 	struct intel_uncore *uncore = rps_to_uncore(rps);
+	struct intel_runtime_pm *rpm = rps_to_uncore(rps)->rpm;
+	intel_wakeref_t wakeref;
+	u32 freq = 0;
 
-	return intel_uncore_read(uncore, GEN6_RPNSWREQ);
+	with_intel_runtime_pm_if_in_use(rpm, wakeref)
+		freq = intel_uncore_read(uncore, GEN6_RPNSWREQ);
+
+	return freq;
 }
 
 static u32 intel_rps_get_req(u32 pureq)
-- 
2.25.1