drm/i915: Get PM ref before accessing HW register

vsbelgaum · jnikula · commit 00598d5c6931 · 2021-09-14T10:57:14.000+03:00
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@intel.com> Fixes: 41e5c17 ("drm/i915/guc/slpc: Sysfs hooks for SLPC") Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: John Harrison <John.C.Harrison@Intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210907232704.12982-1-vinay.belgaumkar@intel.com (cherry picked from commit f25e390) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
@@ -1973,8 +1973,14 @@ 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)

Original file line number	Diff line number	Diff line change
`@@ -1973,8 +1973,14 @@ u32 intel_rps_read_actual_frequency(struct intel_rps *rps)`
`1973`	`1973`	`u32 intel_rps_read_punit_req(struct intel_rps *rps)`
`1974`	`1974`	`{`
`1975`	`1975`	`struct intel_uncore *uncore = rps_to_uncore(rps);`
	`1976`	`+ struct intel_runtime_pm *rpm = rps_to_uncore(rps)->rpm;`
	`1977`	`+ intel_wakeref_t wakeref;`
	`1978`	`+ u32 freq = 0;`
`1976`	`1979`
`1977`		`- return intel_uncore_read(uncore, GEN6_RPNSWREQ);`
	`1980`	`+ with_intel_runtime_pm_if_in_use(rpm, wakeref)`
	`1981`	`+ freq = intel_uncore_read(uncore, GEN6_RPNSWREQ);`
	`1982`	`+`
	`1983`	`+ return freq;`
`1978`	`1984`	`}`
`1979`	`1985`
`1980`	`1986`	`static u32 intel_rps_get_req(u32 pureq)`