On Wed, Jun 10, 2026 at 11:54:19AM +0800, Guangshuo Li wrote:
> intel_crtc_free_hw_state() drops the CRTC color blob references, but
> leaves the corresponding pointers unchanged.
>
> This can matter in intel_crtc_prepare_cleared_state(), which frees the
> old CRTC hw state before calling intel_dp_tunnel_atomic_clear_stream_bw().
> The latter can fail while looking up the DP tunnel group state, for
> example with -EDEADLK.
>
> If that happens, the function returns without completing the cleared
> state preparation. The failed atomic state will then be cleared by the
> atomic core and intel_crtc_free_hw_state() can be called again for the
> same state, dropping the same blob references again.
>
> Clear the blob pointers after dropping the references so repeated cleanup
> of the same CRTC hw state is safe.
>
> Fixes: fb69d0076e68 ("drm/i915/dp_tunnel: Fix error handling when clearing
> stream BW in atomic state")
> Suggested-by: Imre Deak <[email protected]>
> Signed-off-by: Guangshuo Li <[email protected]>
> ---
> v2:
> - Keep the original ordering in intel_crtc_prepare_cleared_state().
> - Clear the blob reference pointers in intel_crtc_free_hw_state(), as
> suggested by Imre.
>
> drivers/gpu/drm/i915/display/intel_atomic.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c
> b/drivers/gpu/drm/i915/display/intel_atomic.c
> index 71b7325917b6..0cdae87e4bfc 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> @@ -294,6 +294,12 @@ static void intel_crtc_put_color_blobs(struct
> intel_crtc_state *crtc_state)
> void intel_crtc_free_hw_state(struct intel_crtc_state *crtc_state)
> {
> intel_crtc_put_color_blobs(crtc_state);
> +
> + crtc_state->hw.degamma_lut = NULL;
> + crtc_state->hw.gamma_lut = NULL;
> + crtc_state->hw.ctm = NULL;
> + crtc_state->pre_csc_lut = NULL;
> + crtc_state->post_csc_lut = NULL;
> }
Could you still move the clearing closer where the refs are dropped, to
the end of intel_crtc_put_color_blobs()? Otherwise this looks ok to me.
>
> /**
> --
> 2.43.0
>
