[PATCH] drm/i915/gt: Ensure sleep calculations in wait_for_freq() do not use negative value of timeout_ms

[Krzysztof Karas]

wait_for_freq() allows timeout_ms to be negative to pass it down
to msecs_to_jiffies(). If the argument to the latter function is
indeed negative, then MAX_JIFFY_OFFSET is returned from it.

However, later in the wait_for_freq()'s "do while" loop,
"timeout_ms" is used to calculate a new value for "sleep", which
is a plain integer. While "sleep" being negative does not lead
to erroneous behavior, as the "sleep" is cast to unsigned type
in usleep_range(), it does not seem intentional.

Change the type of "sleep" variable to unsigned and ensure it
does not use "timeout_ms", when it is a negative value in the
calculations.

Signed-off-by: Krzysztof Karas <krzysztof.karas at intel.com>
---
 drivers/gpu/drm/i915/gt/selftest_rps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_rps.c b/drivers/gpu/drm/i915/gt/selftest_rps.c
index 73bc91c6ea07..20ec7c0c94dc 100644
--- a/drivers/gpu/drm/i915/gt/selftest_rps.c
+++ b/drivers/gpu/drm/i915/gt/selftest_rps.c
@@ -152,7 +152,7 @@ static u8 wait_for_freq(struct intel_rps *rps, u8 freq, int timeout_ms)
 {
 	u8 history[64], i;
 	unsigned long end;
-	int sleep;
+	unsigned int sleep;
 
 	i = 0;
 	memset(history, freq, sizeof(history));
@@ -180,7 +180,7 @@ static u8 wait_for_freq(struct intel_rps *rps, u8 freq, int timeout_ms)
 
 		usleep_range(sleep, 2 * sleep);
 		sleep *= 2;
-		if (sleep > timeout_ms * 20)
+		if (sleep > timeout_ms * 20 && timeout_ms > 0)
 			sleep = timeout_ms * 20;
 	} while (1);
 }
-- 
2.34.1

-- 
Best Regards,
Krzysztof