On Fri, Mar 20, 2026 at 11:20:28AM +0100, Michał Grzelak wrote: > On Fri, 20 Mar 2026, Imre Deak wrote: > > Clearing the DP tunnel stream BW in the atomic state involves getting > > the tunnel group state, which can fail. Handle the error accordingly. > > > > This fixes at least one issue where drm_dp_tunnel_atomic_set_stream_bw() > > failed to get the tunnel group state returning -EDEADLK, which wasn't > > handled. This lead to the ctx->contended warn later in modeset_lock() > > while taking a WW mutex for another object in the same atomic state, and > > thus within the same already contended WW context. > > > > Moving intel_crtc_state_alloc() later would avoid freeing saved_state on > > the error path; this stable patch leaves that simplification for a > > follow-up. > > > > Cc: Uma Shankar <[email protected]> > > Cc: Ville Syrjälä <[email protected]> > > Cc: <[email protected]> # v6.9+ > > Fixes: a4efae87ecb2 ("drm/i915/dp: Compute DP tunnel BW during encoder > > state computation") > > Signed-off-by: Imre Deak <[email protected]> > > --- > > drivers/gpu/drm/i915/display/intel_display.c | 8 +++++++- > > .../gpu/drm/i915/display/intel_dp_tunnel.c | 20 +++++++++++++------ > > .../gpu/drm/i915/display/intel_dp_tunnel.h | 11 ++++++---- > > 3 files changed, 28 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c > > b/drivers/gpu/drm/i915/display/intel_display.c > > index ee501009a251f..882db77c0bbcd 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display.c > > +++ b/drivers/gpu/drm/i915/display/intel_display.c > > @@ -4640,6 +4640,7 @@ intel_crtc_prepare_cleared_state(struct > > intel_atomic_state *state, > > struct intel_crtc_state *crtc_state = > > intel_atomic_get_new_crtc_state(state, crtc); > > struct intel_crtc_state *saved_state; > > + int err; > > > > saved_state = intel_crtc_state_alloc(crtc); > > if (!saved_state) > > @@ -4648,7 +4649,12 @@ intel_crtc_prepare_cleared_state(struct > > intel_atomic_state *state, > > /* free the old crtc_state->hw members */ > > intel_crtc_free_hw_state(crtc_state); > > > > - intel_dp_tunnel_atomic_clear_stream_bw(state, crtc_state); > > + err = intel_dp_tunnel_atomic_clear_stream_bw(state, crtc_state); > > + if (err) { > > + kfree(saved_state); > > + > > I am unsure if the blank line above is neccessary,
Yes, it's used for readability before returns. > but I might be also > missing style guidelines. Otherwise looks good to me. > > Reviewed-by: Michał Grzelak <[email protected]> > > BR, > Michał > > > + return err; > > + } > > > > /* FIXME: before the switch to atomic started, a new pipe_config was > > * kzalloc'd. Code that depends on any field being zero should be > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_tunnel.c > > b/drivers/gpu/drm/i915/display/intel_dp_tunnel.c > > index 1fd1ac8d556d8..7363c98172971 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_tunnel.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp_tunnel.c > > @@ -659,19 +659,27 @@ int intel_dp_tunnel_atomic_compute_stream_bw(struct > > intel_atomic_state *state, > > * > > * Clear any DP tunnel stream BW requirement set by > > * intel_dp_tunnel_atomic_compute_stream_bw(). > > + * > > + * Returns 0 in case of success, a negative error code otherwise. > > */ > > -void intel_dp_tunnel_atomic_clear_stream_bw(struct intel_atomic_state > > *state, > > - struct intel_crtc_state *crtc_state) > > +int intel_dp_tunnel_atomic_clear_stream_bw(struct intel_atomic_state > > *state, > > + struct intel_crtc_state *crtc_state) > > { > > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > > + int err; > > > > if (!crtc_state->dp_tunnel_ref.tunnel) > > - return; > > + return 0; > > + > > + err = drm_dp_tunnel_atomic_set_stream_bw(&state->base, > > + > > crtc_state->dp_tunnel_ref.tunnel, > > + crtc->pipe, 0); > > + if (err) > > + return err; > > > > - drm_dp_tunnel_atomic_set_stream_bw(&state->base, > > - crtc_state->dp_tunnel_ref.tunnel, > > - crtc->pipe, 0); > > drm_dp_tunnel_ref_put(&crtc_state->dp_tunnel_ref); > > + > > + return 0; > > } > > > > /** > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_tunnel.h > > b/drivers/gpu/drm/i915/display/intel_dp_tunnel.h > > index 7f0f720e8dcad..10ab9eebcef69 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp_tunnel.h > > +++ b/drivers/gpu/drm/i915/display/intel_dp_tunnel.h > > @@ -40,8 +40,8 @@ int intel_dp_tunnel_atomic_compute_stream_bw(struct > > intel_atomic_state *state, > > struct intel_dp *intel_dp, > > const struct intel_connector > > *connector, > > struct intel_crtc_state > > *crtc_state); > > -void intel_dp_tunnel_atomic_clear_stream_bw(struct intel_atomic_state > > *state, > > - struct intel_crtc_state > > *crtc_state); > > +int intel_dp_tunnel_atomic_clear_stream_bw(struct intel_atomic_state > > *state, > > + struct intel_crtc_state *crtc_state); > > > > int intel_dp_tunnel_atomic_add_state_for_crtc(struct intel_atomic_state > > *state, > > struct intel_crtc *crtc); > > @@ -88,9 +88,12 @@ intel_dp_tunnel_atomic_compute_stream_bw(struct > > intel_atomic_state *state, > > return 0; > > } > > > > -static inline void > > +static inline int > > intel_dp_tunnel_atomic_clear_stream_bw(struct intel_atomic_state *state, > > - struct intel_crtc_state *crtc_state) {} > > + struct intel_crtc_state *crtc_state) > > +{ > > + return 0; > > +} > > > > static inline int > > intel_dp_tunnel_atomic_add_state_for_crtc(struct intel_atomic_state *state, > > -- > > 2.49.1 > > > >
