| Message ID | 1626196421-24595-1-git-send-email-gracan@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | [RFC] drm: return int error code from mode_fixup | expand |
On Tue, Jul 13, 2021 at 7:14 PM Grace An <gracan@codeaurora.org> wrote: > When CONFIG_PROVE_LOCKING is defined, the kernel randomly injects > -EDEADLK errors for all the ww_mutex. This results in > drm_atomic_get_private_obj_state randomly returning -EDEADLK. > However, the mode_fixup functions do not propagate these error > codes and return false, causing the atomic commit to fail with > -EINVAL instead of retrying. > > Change encoder, crtc, and bridge mode_fixup functions to return > an int instead of a boolean to indicate success or failure. If > any of these functions fail, the mode_fixup function now returns > the provided integer error code instead of -EINVAL. > > This change needs modifications across drivers, but before submitting > the entire change, we want to get feedback on this RFC. > > Signed-off-by: Grace An <gracan@codeaurora.org> Why don't you just use the various atomic_check hooks we have for this? There you get passed the state and everything, have a full int return value, and things actually work. ->mode_fixup is for compatibility with legacy crtc modeset helpers from the pre-atomic times. If the kerneldoc isn't clear yet, please do a patch to fix that up so that @mode_fixup points at the relevant @atomic_check as the recommended function. -Daniel > --- > drivers/gpu/drm/drm_atomic_helper.c | 8 ++++---- > drivers/gpu/drm/drm_bridge.c | 4 ++-- > include/drm/drm_bridge.h | 2 +- > include/drm/drm_modeset_helper_vtables.h | 4 ++-- > 4 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index f2b3e28..d75f09a 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -457,10 +457,10 @@ mode_fixup(struct drm_atomic_state *state) > } else if (funcs && funcs->mode_fixup) { > ret = funcs->mode_fixup(encoder, &new_crtc_state->mode, > &new_crtc_state->adjusted_mode); > - if (!ret) { > + if (ret) { > DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n", > encoder->base.id, encoder->name); > - return -EINVAL; > + return ret; > } > } > } > @@ -481,10 +481,10 @@ mode_fixup(struct drm_atomic_state *state) > > ret = funcs->mode_fixup(crtc, &new_crtc_state->mode, > &new_crtc_state->adjusted_mode); > - if (!ret) { > + if (ret) { > DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n", > crtc->base.id, crtc->name); > - return -EINVAL; > + return ret; > } > } > > diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c > index 64f0eff..3ad16b5 100644 > --- a/drivers/gpu/drm/drm_bridge.c > +++ b/drivers/gpu/drm/drm_bridge.c > @@ -736,9 +736,9 @@ static int drm_atomic_bridge_check(struct drm_bridge *bridge, > if (ret) > return ret; > } else if (bridge->funcs->mode_fixup) { > - if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode, > + if (bridge->funcs->mode_fixup(bridge, &crtc_state->mode, > &crtc_state->adjusted_mode)) > - return -EINVAL; > + return ret; > } > > return 0; > diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h > index 2195daa..5d02dfc 100644 > --- a/include/drm/drm_bridge.h > +++ b/include/drm/drm_bridge.h > @@ -153,7 +153,7 @@ struct drm_bridge_funcs { > * True if an acceptable configuration is possible, false if the modeset > * operation should be rejected. > */ > - bool (*mode_fixup)(struct drm_bridge *bridge, > + int (*mode_fixup)(struct drm_bridge *bridge, > const struct drm_display_mode *mode, > struct drm_display_mode *adjusted_mode); > /** > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index f3a4b47..e305c97 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -184,7 +184,7 @@ struct drm_crtc_helper_funcs { > * True if an acceptable configuration is possible, false if the modeset > * operation should be rejected. > */ > - bool (*mode_fixup)(struct drm_crtc *crtc, > + int (*mode_fixup)(struct drm_crtc *crtc, > const struct drm_display_mode *mode, > struct drm_display_mode *adjusted_mode); > > @@ -599,7 +599,7 @@ struct drm_encoder_helper_funcs { > * True if an acceptable configuration is possible, false if the modeset > * operation should be rejected. > */ > - bool (*mode_fixup)(struct drm_encoder *encoder, > + int (*mode_fixup)(struct drm_encoder *encoder, > const struct drm_display_mode *mode, > struct drm_display_mode *adjusted_mode); > > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index f2b3e28..d75f09a 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -457,10 +457,10 @@ mode_fixup(struct drm_atomic_state *state) } else if (funcs && funcs->mode_fixup) { ret = funcs->mode_fixup(encoder, &new_crtc_state->mode, &new_crtc_state->adjusted_mode); - if (!ret) { + if (ret) { DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n", encoder->base.id, encoder->name); - return -EINVAL; + return ret; } } } @@ -481,10 +481,10 @@ mode_fixup(struct drm_atomic_state *state) ret = funcs->mode_fixup(crtc, &new_crtc_state->mode, &new_crtc_state->adjusted_mode); - if (!ret) { + if (ret) { DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n", crtc->base.id, crtc->name); - return -EINVAL; + return ret; } } diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 64f0eff..3ad16b5 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -736,9 +736,9 @@ static int drm_atomic_bridge_check(struct drm_bridge *bridge, if (ret) return ret; } else if (bridge->funcs->mode_fixup) { - if (!bridge->funcs->mode_fixup(bridge, &crtc_state->mode, + if (bridge->funcs->mode_fixup(bridge, &crtc_state->mode, &crtc_state->adjusted_mode)) - return -EINVAL; + return ret; } return 0; diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 2195daa..5d02dfc 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -153,7 +153,7 @@ struct drm_bridge_funcs { * True if an acceptable configuration is possible, false if the modeset * operation should be rejected. */ - bool (*mode_fixup)(struct drm_bridge *bridge, + int (*mode_fixup)(struct drm_bridge *bridge, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode); /** diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index f3a4b47..e305c97 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -184,7 +184,7 @@ struct drm_crtc_helper_funcs { * True if an acceptable configuration is possible, false if the modeset * operation should be rejected. */ - bool (*mode_fixup)(struct drm_crtc *crtc, + int (*mode_fixup)(struct drm_crtc *crtc, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode); @@ -599,7 +599,7 @@ struct drm_encoder_helper_funcs { * True if an acceptable configuration is possible, false if the modeset * operation should be rejected. */ - bool (*mode_fixup)(struct drm_encoder *encoder, + int (*mode_fixup)(struct drm_encoder *encoder, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode);
When CONFIG_PROVE_LOCKING is defined, the kernel randomly injects -EDEADLK errors for all the ww_mutex. This results in drm_atomic_get_private_obj_state randomly returning -EDEADLK. However, the mode_fixup functions do not propagate these error codes and return false, causing the atomic commit to fail with -EINVAL instead of retrying. Change encoder, crtc, and bridge mode_fixup functions to return an int instead of a boolean to indicate success or failure. If any of these functions fail, the mode_fixup function now returns the provided integer error code instead of -EINVAL. This change needs modifications across drivers, but before submitting the entire change, we want to get feedback on this RFC. Signed-off-by: Grace An <gracan@codeaurora.org> --- drivers/gpu/drm/drm_atomic_helper.c | 8 ++++---- drivers/gpu/drm/drm_bridge.c | 4 ++-- include/drm/drm_bridge.h | 2 +- include/drm/drm_modeset_helper_vtables.h | 4 ++-- 4 files changed, 9 insertions(+), 9 deletions(-)