[PATCH v2 2/2] drm/i915/psr: check drm_mode_vrefresh return value

[Ville Syrjälä]

On Thu, Aug 21, 2025 at 07:59:18AM +0300, Jouni Högander wrote:
> 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 5addde63168e..8cc2314fac6f 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)

How would that happen?

> +		return 0;
> +
> +	return DIV_ROUND_UP(1000 * 1000, vrefresh);
>  }
>  
>  static void psr2_program_idle_frames(struct intel_dp *intel_dp,
> -- 
> 2.43.0

-- 
Ville Syrjälä
Intel