[PATCH 2/2] drm/i915/psr: check drm_mode_vrefresh return value

[Jouni Högander]

Check drm_mode_vrefresh return value sanity before using it in
intel_get_frame_time_us.

Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 68eb02127f47..79ba5b17ae40 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1116,11 +1116,16 @@ transcoder_has_psr2(struct intel_display *display, enum transcoder cpu_transcode
 
 static u32 intel_get_frame_time_us(const struct intel_crtc_state *crtc_state)
 {
+	int vrefresh;
+
 	if (!crtc_state->hw.active)
 		return 0;
 
-	return DIV_ROUND_UP(1000 * 1000,
-			    drm_mode_vrefresh(&crtc_state->hw.adjusted_mode));
+	vrefresh = drm_mode_vrefresh(&crtc_state->hw.adjusted_mode);
+	if (vrefresh <= 0)
+		return 0;
+
+	return DIV_ROUND_UP(1000 * 1000, vrefresh);
 }
 
 static void psr2_program_idle_frames(struct intel_dp *intel_dp,
-- 
2.43.0