drm/i915/gt: Use proper sleeping functions for timeouts shorter than 20ms

msleep is very imprecise for timeouts shorter than 20
milliseconds and most probably will sleep longer. Use
uslee_range() instead.

Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Sebastian Brzezinka <sebastian.brzezinka@intel.com>
Reviewed-by: Krzysztof Karas <krzysztof.karas@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250314021225.11813-5-andi.shyti@linux.intel.com

Author: Andi Shyti

drivers/gpu/drm/i915/gt/selftest_rc6.c

@@ -60,7 +60,8 @@ int live_rc6_manual(void *arg)
 
 	/* Force RC6 off for starters */
 	__intel_rc6_disable(rc6);
-	msleep(1); /* wakeup is not immediate, takes about 100us on icl */
+	/* wakeup is not immediate, takes about 100us on icl */
+	usleep_range(1000, 2000);
 
 	res[0] = rc6_residency(rc6);
 

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

@@ -143,7 +143,7 @@ pte_tlbinv(struct intel_context *ce,
 	if (ce->engine->class == OTHER_CLASS)
 		msleep(200);
 	else
-		msleep(10);
+		usleep_range(10000, 20000);
 
 	if (va == vb) {
 		if (!i915_request_completed(rq)) {