Commit 4d14d771 authored by Anshuman Gupta's avatar Anshuman Gupta
Browse files

drm/i915/selftest: Fix ktime_get() and h/w access order 



Use ktime_get() after accessing the mmio or any driver resource,
while using wall time for various calculation that depends on
the inserted delay in order to account any mmio and resource
access latency.

Cc: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: default avatarAnshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: default avatarBadal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230223100503.3323627-3-anshuman.gupta@intel.com
parent 29b41cf7

drivers/gpu/drm/i915/gt/selftest_rps.c

+3 −3
Original line number Diff line number Diff line
@@ -537,8 +537,8 @@ static u64 __measure_frequency(u32 *cntr, int duration_ms) 
{

	u64 dc, dt;



	dt = ktime_get();

	dc = READ_ONCE(*cntr);

	dt = ktime_get();

	usleep_range(1000 * duration_ms, 2000 * duration_ms);

	dc = READ_ONCE(*cntr) - dc;

	dt = ktime_get() - dt;
@@ -566,8 +566,8 @@ static u64 __measure_cs_frequency(struct intel_engine_cs *engine, 
{

	u64 dc, dt;



	dt = ktime_get();

	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0));

	dt = ktime_get();

	usleep_range(1000 * duration_ms, 2000 * duration_ms);

	dc = intel_uncore_read_fw(engine->uncore, CS_GPR(0)) - dc;

	dt = ktime_get() - dt;
@@ -1094,8 +1094,8 @@ static u64 __measure_power(int duration_ms) 
{

	u64 dE, dt;



	dt = ktime_get();

	dE = librapl_energy_uJ();

	dt = ktime_get();

	usleep_range(1000 * duration_ms, 2000 * duration_ms);

	dE = librapl_energy_uJ() - dE;

	dt = ktime_get() - dt;