On 7/9/2024 6:48 AM, Dmitry Baryshkov wrote:

In order to prevent any errors on connector being disabled, move the state->crtc check upfront. This should fix the issues during suspend when the writeback connector gets forcebly disabled.

Fixes: 71174f362d67 ("drm/msm/dpu: move writeback's atomic_check to dpu_writeback.c") Cc: stable@vger.kernel.org Reported-by: Leonard Lausen leonard@lausen.nl Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/57 Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org

---

drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c index 16f144cbc0c9..5c172bcf3419 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c @@ -39,6 +39,13 @@ static int dpu_wb_conn_atomic_check(struct drm_connector *connector, DPU_DEBUG("[atomic_check:%d]\n", connector->base.id);

• crtc = conn_state->crtc;

We are checking for !conn_state a few lines below but we are dereferencing conn_state here.

This is bound to hit a smatch error and also does not look right.

If conn_state will always be valid, we should drop that check too rather than checking it later.

Coming to the issue itself, I tried checking the logs but it was not clear.

During force disable, were we hitting below check and hence the connector was not getting disabled?

else if (conn_state->connector->status != connector_status_connected) { DPU_ERROR("connector not connected %d\n", conn_state->connector->status); return -EINVAL; }

I did not see this error log there, so can you pls explain where we were bailing out? The check seems valid to me.

• if (!crtc)

• return 0;
  

• if (!conn_state->writeback_job || !conn_state->writeback_job->fb)

• return 0;
  

• if (!conn_state || !conn_state->connector) { DPU_ERROR("invalid connector state\n"); return -EINVAL;

@@ -47,13 +54,6 @@ static int dpu_wb_conn_atomic_check(struct drm_connector *connector, return -EINVAL; }

• crtc = conn_state->crtc;
• if (!crtc)

• return 0;
  

• if (!conn_state->writeback_job || !conn_state->writeback_job->fb)

• return 0;
  

• crtc_state = drm_atomic_get_crtc_state(state, crtc); if (IS_ERR(crtc_state)) return PTR_ERR(crtc_state);