Re: [PATCH v2 18/24] drm/msm: dpu: Remove crtc_lock from setup_mixers

Jeykumar Sankaran
2018-11-19T20:09:56Z

On 2018-11-16 10:42, Sean Paul wrote:
> From: Sean Paul <seanpaul@chromium.org>
>
> I think the intention here was to protect the enc->crtc access, but
> that's insufficient to avoid enc->crtc changing. Fortunately we're
> already holding the modeset lock when this is called (from
> atomic_check), so remove the crtc_lock and add a modeset lock check.
>
> While we're at it, use the encoder mask from crtc state instead of
> legacy pointer.
>
> Changes in v2:
> - None
>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>

Reviewed-by: Jeykumar Sankaran <jsanka@codeaurora.org>

> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index c49aaf412b6e..141ed1b0e90a 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -474,19 +474,13 @@ static void _dpu_crtc_setup_mixer_for_encoder(
>
> static void _dpu_crtc_setup_mixers(struct drm_crtc *crtc)
> {
> - struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
> struct drm_encoder *enc;
>
> - mutex_lock(&dpu_crtc->crtc_lock);
> - /* Check for mixers on all encoders attached to this crtc */
> - list_for_each_entry(enc, &crtc->dev->mode_config.encoder_list,
> head) {
> - if (enc->crtc != crtc)
> - continue;
> + WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
>
> + /* Check for mixers on all encoders attached to this crtc */
> + drm_for_each_encoder_mask(enc, crtc->dev,
> crtc->state->encoder_mask)
> _dpu_crtc_setup_mixer_for_encoder(crtc, enc);
> - }
> -
> - mutex_unlock(&dpu_crtc->crtc_lock);
> }
>
> static void _dpu_crtc_setup_lm_bounds(struct drm_crtc *crtc,

--
Jeykumar S