| Message ID | 20200526182313.4005-2-lyude@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/probe_helper, i915: Validate MST modes against PBN limits | expand |
Sorry for the delay, the review as I promised: On Tue, May 26, 2020 at 02:23:09PM -0400, Lyude Paul wrote: > This is just an atomic version of mode_valid, which is intended to be > used for situations where a driver might need to check the atomic state > of objects other than the connector itself. One such example is with > MST, where the maximum possible bandwidth on a connector can change > dynamically irregardless of the display configuration. > > Signed-off-by: Lyude Paul <lyude@redhat.com> > Cc: Lee Shawn C <shawn.c.lee@intel.com> > Tested-by: Lee Shawn C <shawn.c.lee@intel.com> > --- > drivers/gpu/drm/drm_crtc_helper_internal.h | 6 +- > drivers/gpu/drm/drm_probe_helper.c | 65 ++++++++++++++-------- > include/drm/drm_modeset_helper_vtables.h | 41 ++++++++++++++ > 3 files changed, 88 insertions(+), 24 deletions(-) > > diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h > index f0a66ef47e5ad..ca767cba6094d 100644 > --- a/drivers/gpu/drm/drm_crtc_helper_internal.h > +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h > @@ -73,8 +73,10 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc, > const struct drm_display_mode *mode); > enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, > const struct drm_display_mode *mode); > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, > - struct drm_display_mode *mode); > +enum drm_mode_status > +drm_connector_mode_valid(struct drm_connector *connector, > + struct drm_display_mode *mode, > + struct drm_modeset_acquire_ctx *ctx); > > struct drm_encoder * > drm_connector_get_single_encoder(struct drm_connector *connector); > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index 466dfbba82564..3132784736841 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -86,16 +86,17 @@ drm_mode_validate_flag(const struct drm_display_mode *mode, > return MODE_OK; > } > > -static enum drm_mode_status > +static int > drm_mode_validate_pipeline(struct drm_display_mode *mode, > - struct drm_connector *connector) > + struct drm_connector *connector, > + struct drm_modeset_acquire_ctx *ctx) > { > struct drm_device *dev = connector->dev; > - enum drm_mode_status ret = MODE_OK; > struct drm_encoder *encoder; > + int ret = MODE_OK; > > /* Step 1: Validate against connector */ > - ret = drm_connector_mode_valid(connector, mode); > + ret = drm_connector_mode_valid(connector, mode, ctx); > if (ret != MODE_OK) > return ret; > > @@ -196,16 +197,23 @@ enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, > return encoder_funcs->mode_valid(encoder, mode); > } > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, > - struct drm_display_mode *mode) > +int > +drm_connector_mode_valid(struct drm_connector *connector, > + struct drm_display_mode *mode, > + struct drm_modeset_acquire_ctx *ctx) > { > const struct drm_connector_helper_funcs *connector_funcs = > connector->helper_private; > > - if (!connector_funcs || !connector_funcs->mode_valid) > + if (!connector_funcs) > return MODE_OK; > > - return connector_funcs->mode_valid(connector, mode); > + if (connector_funcs->mode_valid_ctx) > + return connector_funcs->mode_valid_ctx(connector, mode, ctx); > + else if (connector_funcs->mode_valid) > + return connector_funcs->mode_valid(connector, mode); > + else > + return MODE_OK; > } > > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > @@ -375,8 +383,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); > * (if specified) > * - drm_mode_validate_flag() checks the modes against basic connector > * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) > - * - the optional &drm_connector_helper_funcs.mode_valid helper can perform > - * driver and/or sink specific checks > + * - the optional &drm_connector_helper_funcs.mode_valid or > + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver > + * and/or sink specific checks > * - the optional &drm_crtc_helper_funcs.mode_valid, > * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid > * helpers can perform driver and/or source specific checks which are also > @@ -507,22 +516,34 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, > mode_flags |= DRM_MODE_FLAG_3D_MASK; > > list_for_each_entry(mode, &connector->modes, head) { > - if (mode->status == MODE_OK) > - mode->status = drm_mode_validate_driver(dev, mode); > + if (mode->status != MODE_OK) > + continue; > + > + mode->status = drm_mode_validate_driver(dev, mode); > + if (mode->status != MODE_OK) > + continue; > > - if (mode->status == MODE_OK) > - mode->status = drm_mode_validate_size(mode, maxX, maxY); > + mode->status = drm_mode_validate_size(mode, maxX, maxY); > + if (mode->status != MODE_OK) > + continue; > > - if (mode->status == MODE_OK) > - mode->status = drm_mode_validate_flag(mode, mode_flags); > + mode->status = drm_mode_validate_flag(mode, mode_flags); > + if (mode->status != MODE_OK) > + continue; > > - if (mode->status == MODE_OK) > - mode->status = drm_mode_validate_pipeline(mode, > - connector); > + ret = drm_mode_validate_pipeline(mode, connector, &ctx); > + if (ret == -EDEADLK) { > + drm_modeset_backoff(&ctx); > + goto retry; > + } else if (WARN_ON_ONCE(ret < 0)) { > + mode->status = MODE_BAD; > + } else { > + mode->status = ret; > + } > > - if (mode->status == MODE_OK) > - mode->status = drm_mode_validate_ycbcr420(mode, > - connector); > + if (mode->status != MODE_OK) > + continue; > + mode->status = drm_mode_validate_ycbcr420(mode, connector); > } > > prune: > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index 421a30f084631..8f020c3424b2b 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -968,6 +968,47 @@ struct drm_connector_helper_funcs { > */ > enum drm_mode_status (*mode_valid)(struct drm_connector *connector, > struct drm_display_mode *mode); > + > + /** > + * @mode_valid_ctx: > + * > + * Callback to validate a mode for a connector, irrespective of the > + * specific display configuration. > + * > + * This callback is used by the probe helpers to filter the mode list > + * (which is usually derived from the EDID data block from the sink). > + * See e.g. drm_helper_probe_single_connector_modes(). > + * > + * This function is optional, and is the atomic version of > + * &drm_connector_funcs.mode_valid. > + * > + * To allow for accessing the atomic state of modesetting objects, the > + * helper libraries always call this with ctx set to a valid context, > + * and &drm_mode_config.connection_mutex will always be locked with > + * the ctx parameter set to @ctx. This allows for taking additional > + * locks as required. > + * > + * Even though additional locks may be acquired, this callback is > + * still expected not to take any constraints into account which would > + * be influenced by the currently set display state - such constraints > + * should be handled in the driver's atomic check. For example, if a > + * connector shares display bandwidth with other connectors then it > + * would be ok to validate a mode uses against the maximum possible ^mode against? Reviewed-by: Imre Deak <imre.deak@intel.com> > + * bandwidth of the connector. But it wouldn't be ok to take the > + * current bandwidth usage of other connectors into account, as this > + * would change depending on the display state. > + * > + * Returns: > + * > + * Either &drm_mode_status.MODE_OK, one of the failure reasons in > + * &enum drm_mode_status, or -EDEADLK if a deadlock would have > + * occurred and we need to backoff. > + * > + */ > + int (*mode_valid_ctx)(struct drm_connector *connector, > + struct drm_display_mode *mode, > + struct drm_modeset_acquire_ctx *ctx); > + > /** > * @best_encoder: > * > -- > 2.26.2 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
JFYI - found an issue with this patch that wouldn't have shown up on i915, info down below: On Wed, 2020-07-08 at 01:40 +0300, Imre Deak wrote: > Sorry for the delay, the review as I promised: > > On Tue, May 26, 2020 at 02:23:09PM -0400, Lyude Paul wrote: > > This is just an atomic version of mode_valid, which is intended to be > > used for situations where a driver might need to check the atomic state > > of objects other than the connector itself. One such example is with > > MST, where the maximum possible bandwidth on a connector can change > > dynamically irregardless of the display configuration. > > > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > Cc: Lee Shawn C <shawn.c.lee@intel.com> > > Tested-by: Lee Shawn C <shawn.c.lee@intel.com> > > --- > > drivers/gpu/drm/drm_crtc_helper_internal.h | 6 +- > > drivers/gpu/drm/drm_probe_helper.c | 65 ++++++++++++++-------- > > include/drm/drm_modeset_helper_vtables.h | 41 ++++++++++++++ > > 3 files changed, 88 insertions(+), 24 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h > > b/drivers/gpu/drm/drm_crtc_helper_internal.h > > index f0a66ef47e5ad..ca767cba6094d 100644 > > --- a/drivers/gpu/drm/drm_crtc_helper_internal.h > > +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h > > @@ -73,8 +73,10 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc > > *crtc, > > const struct drm_display_mode *mode); > > enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, > > const struct drm_display_mode > > *mode); > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > *connector, > > - struct drm_display_mode *mode); > > +enum drm_mode_status > > +drm_connector_mode_valid(struct drm_connector *connector, > > + struct drm_display_mode *mode, > > + struct drm_modeset_acquire_ctx *ctx); > > > > struct drm_encoder * > > drm_connector_get_single_encoder(struct drm_connector *connector); > > diff --git a/drivers/gpu/drm/drm_probe_helper.c > > b/drivers/gpu/drm/drm_probe_helper.c > > index 466dfbba82564..3132784736841 100644 > > --- a/drivers/gpu/drm/drm_probe_helper.c > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > @@ -86,16 +86,17 @@ drm_mode_validate_flag(const struct drm_display_mode > > *mode, > > return MODE_OK; > > } > > > > -static enum drm_mode_status > > +static int > > drm_mode_validate_pipeline(struct drm_display_mode *mode, > > - struct drm_connector *connector) > > + struct drm_connector *connector, > > + struct drm_modeset_acquire_ctx *ctx) > > { > > struct drm_device *dev = connector->dev; > > - enum drm_mode_status ret = MODE_OK; > > struct drm_encoder *encoder; > > + int ret = MODE_OK; > > > > /* Step 1: Validate against connector */ > > - ret = drm_connector_mode_valid(connector, mode); > > + ret = drm_connector_mode_valid(connector, mode, ctx); > > if (ret != MODE_OK) > > return ret; > > > > @@ -196,16 +197,23 @@ enum drm_mode_status drm_encoder_mode_valid(struct > > drm_encoder *encoder, > > return encoder_funcs->mode_valid(encoder, mode); > > } > > > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > *connector, > > - struct drm_display_mode *mode) > > +int > > +drm_connector_mode_valid(struct drm_connector *connector, > > + struct drm_display_mode *mode, > > + struct drm_modeset_acquire_ctx *ctx) > > { > > const struct drm_connector_helper_funcs *connector_funcs = > > connector->helper_private; > > > > - if (!connector_funcs || !connector_funcs->mode_valid) > > + if (!connector_funcs) > > return MODE_OK; > > > > - return connector_funcs->mode_valid(connector, mode); > > + if (connector_funcs->mode_valid_ctx) > > + return connector_funcs->mode_valid_ctx(connector, mode, ctx); > > + else if (connector_funcs->mode_valid) > > + return connector_funcs->mode_valid(connector, mode); > > + else > > + return MODE_OK; > > } > > > > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > > @@ -375,8 +383,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); > > * (if specified) > > * - drm_mode_validate_flag() checks the modes against basic connector > > * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) > > - * - the optional &drm_connector_helper_funcs.mode_valid helper can > > perform > > - * driver and/or sink specific checks > > + * - the optional &drm_connector_helper_funcs.mode_valid or > > + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform > > driver > > + * and/or sink specific checks > > * - the optional &drm_crtc_helper_funcs.mode_valid, > > * &drm_bridge_funcs.mode_valid and > > &drm_encoder_helper_funcs.mode_valid > > * helpers can perform driver and/or source specific checks which are > > also > > @@ -507,22 +516,34 @@ int drm_helper_probe_single_connector_modes(struct > > drm_connector *connector, > > mode_flags |= DRM_MODE_FLAG_3D_MASK; > > > > list_for_each_entry(mode, &connector->modes, head) { > > - if (mode->status == MODE_OK) > > - mode->status = drm_mode_validate_driver(dev, mode); > > + if (mode->status != MODE_OK) > > + continue; > > + > > + mode->status = drm_mode_validate_driver(dev, mode); > > + if (mode->status != MODE_OK) > > + continue; > > > > - if (mode->status == MODE_OK) > > - mode->status = drm_mode_validate_size(mode, maxX, maxY); > > + mode->status = drm_mode_validate_size(mode, maxX, maxY); > > + if (mode->status != MODE_OK) > > + continue; > > > > - if (mode->status == MODE_OK) > > - mode->status = drm_mode_validate_flag(mode, mode_flags); > > + mode->status = drm_mode_validate_flag(mode, mode_flags); > > + if (mode->status != MODE_OK) > > + continue; > > > > - if (mode->status == MODE_OK) > > - mode->status = drm_mode_validate_pipeline(mode, > > - connector); > > + ret = drm_mode_validate_pipeline(mode, connector, &ctx); > > + if (ret == -EDEADLK) { > > + drm_modeset_backoff(&ctx); > > + goto retry; > > + } else if (WARN_ON_ONCE(ret < 0)) { > > + mode->status = MODE_BAD; This check is wrong actually. We define negative values for drm_mode_status (MODE_BAD, MODE_ERROR, MODE_STALE) which, at least with how drivers currently seem to use them, are something we want to treat as not-unexpected errors and not WARN_ON. This is a bit annoying because it does mean there's some overlap between drm_mode_status and some legitimate errno values (EPERM, ENOENT, ESRCH). Luckily I can't see any reason why drivers would want to return those, but I think we should probably print a debugging message when we get any errno values just so developers don't get confused (also going to add a IS_ERR() equivalent for drm_mode_status, but with a different name) > > + } else { > > + mode->status = ret; > > + } > > > > - if (mode->status == MODE_OK) > > - mode->status = drm_mode_validate_ycbcr420(mode, > > - connector); > > + if (mode->status != MODE_OK) > > + continue; > > + mode->status = drm_mode_validate_ycbcr420(mode, connector); > > } > > > > prune: > > diff --git a/include/drm/drm_modeset_helper_vtables.h > > b/include/drm/drm_modeset_helper_vtables.h > > index 421a30f084631..8f020c3424b2b 100644 > > --- a/include/drm/drm_modeset_helper_vtables.h > > +++ b/include/drm/drm_modeset_helper_vtables.h > > @@ -968,6 +968,47 @@ struct drm_connector_helper_funcs { > > */ > > enum drm_mode_status (*mode_valid)(struct drm_connector *connector, > > struct drm_display_mode *mode); > > + > > + /** > > + * @mode_valid_ctx: > > + * > > + * Callback to validate a mode for a connector, irrespective of the > > + * specific display configuration. > > + * > > + * This callback is used by the probe helpers to filter the mode list > > + * (which is usually derived from the EDID data block from the sink). > > + * See e.g. drm_helper_probe_single_connector_modes(). > > + * > > + * This function is optional, and is the atomic version of > > + * &drm_connector_funcs.mode_valid. > > + * > > + * To allow for accessing the atomic state of modesetting objects, the > > + * helper libraries always call this with ctx set to a valid context, > > + * and &drm_mode_config.connection_mutex will always be locked with > > + * the ctx parameter set to @ctx. This allows for taking additional > > + * locks as required. > > + * > > + * Even though additional locks may be acquired, this callback is > > + * still expected not to take any constraints into account which would > > + * be influenced by the currently set display state - such constraints > > + * should be handled in the driver's atomic check. For example, if a > > + * connector shares display bandwidth with other connectors then it > > + * would be ok to validate a mode uses against the maximum possible > ^mode against? > > Reviewed-by: Imre Deak <imre.deak@intel.com> > > > + * bandwidth of the connector. But it wouldn't be ok to take the > > + * current bandwidth usage of other connectors into account, as this > > + * would change depending on the display state. > > + * > > + * Returns: > > + * > > + * Either &drm_mode_status.MODE_OK, one of the failure reasons in > > + * &enum drm_mode_status, or -EDEADLK if a deadlock would have > > + * occurred and we need to backoff. > > + * > > + */ > > + int (*mode_valid_ctx)(struct drm_connector *connector, > > + struct drm_display_mode *mode, > > + struct drm_modeset_acquire_ctx *ctx); > > + > > /** > > * @best_encoder: > > * > > -- > > 2.26.2 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Wed, Jul 08, 2020 at 01:25:14PM -0400, Lyude Paul wrote: > > JFYI - found an issue with this patch that wouldn't have shown up on i915, info > down below: > > On Wed, 2020-07-08 at 01:40 +0300, Imre Deak wrote: > > Sorry for the delay, the review as I promised: > > > > On Tue, May 26, 2020 at 02:23:09PM -0400, Lyude Paul wrote: > > > This is just an atomic version of mode_valid, which is intended to be > > > used for situations where a driver might need to check the atomic state > > > of objects other than the connector itself. One such example is with > > > MST, where the maximum possible bandwidth on a connector can change > > > dynamically irregardless of the display configuration. > > > > > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > > Cc: Lee Shawn C <shawn.c.lee@intel.com> > > > Tested-by: Lee Shawn C <shawn.c.lee@intel.com> > > > --- > > > drivers/gpu/drm/drm_crtc_helper_internal.h | 6 +- > > > drivers/gpu/drm/drm_probe_helper.c | 65 ++++++++++++++-------- > > > include/drm/drm_modeset_helper_vtables.h | 41 ++++++++++++++ > > > 3 files changed, 88 insertions(+), 24 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h > > > b/drivers/gpu/drm/drm_crtc_helper_internal.h > > > index f0a66ef47e5ad..ca767cba6094d 100644 > > > --- a/drivers/gpu/drm/drm_crtc_helper_internal.h > > > +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h > > > @@ -73,8 +73,10 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc > > > *crtc, > > > const struct drm_display_mode *mode); > > > enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, > > > const struct drm_display_mode > > > *mode); > > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > > *connector, > > > - struct drm_display_mode *mode); > > > +enum drm_mode_status > > > +drm_connector_mode_valid(struct drm_connector *connector, > > > + struct drm_display_mode *mode, > > > + struct drm_modeset_acquire_ctx *ctx); > > > > > > struct drm_encoder * > > > drm_connector_get_single_encoder(struct drm_connector *connector); > > > diff --git a/drivers/gpu/drm/drm_probe_helper.c > > > b/drivers/gpu/drm/drm_probe_helper.c > > > index 466dfbba82564..3132784736841 100644 > > > --- a/drivers/gpu/drm/drm_probe_helper.c > > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > > @@ -86,16 +86,17 @@ drm_mode_validate_flag(const struct drm_display_mode > > > *mode, > > > return MODE_OK; > > > } > > > > > > -static enum drm_mode_status > > > +static int > > > drm_mode_validate_pipeline(struct drm_display_mode *mode, > > > - struct drm_connector *connector) > > > + struct drm_connector *connector, > > > + struct drm_modeset_acquire_ctx *ctx) > > > { > > > struct drm_device *dev = connector->dev; > > > - enum drm_mode_status ret = MODE_OK; > > > struct drm_encoder *encoder; > > > + int ret = MODE_OK; > > > > > > /* Step 1: Validate against connector */ > > > - ret = drm_connector_mode_valid(connector, mode); > > > + ret = drm_connector_mode_valid(connector, mode, ctx); > > > if (ret != MODE_OK) > > > return ret; > > > > > > @@ -196,16 +197,23 @@ enum drm_mode_status drm_encoder_mode_valid(struct > > > drm_encoder *encoder, > > > return encoder_funcs->mode_valid(encoder, mode); > > > } > > > > > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > > *connector, > > > - struct drm_display_mode *mode) > > > +int > > > +drm_connector_mode_valid(struct drm_connector *connector, > > > + struct drm_display_mode *mode, > > > + struct drm_modeset_acquire_ctx *ctx) > > > { > > > const struct drm_connector_helper_funcs *connector_funcs = > > > connector->helper_private; > > > > > > - if (!connector_funcs || !connector_funcs->mode_valid) > > > + if (!connector_funcs) > > > return MODE_OK; > > > > > > - return connector_funcs->mode_valid(connector, mode); > > > + if (connector_funcs->mode_valid_ctx) > > > + return connector_funcs->mode_valid_ctx(connector, mode, ctx); > > > + else if (connector_funcs->mode_valid) > > > + return connector_funcs->mode_valid(connector, mode); > > > + else > > > + return MODE_OK; > > > } > > > > > > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > > > @@ -375,8 +383,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); > > > * (if specified) > > > * - drm_mode_validate_flag() checks the modes against basic connector > > > * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) > > > - * - the optional &drm_connector_helper_funcs.mode_valid helper can > > > perform > > > - * driver and/or sink specific checks > > > + * - the optional &drm_connector_helper_funcs.mode_valid or > > > + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform > > > driver > > > + * and/or sink specific checks > > > * - the optional &drm_crtc_helper_funcs.mode_valid, > > > * &drm_bridge_funcs.mode_valid and > > > &drm_encoder_helper_funcs.mode_valid > > > * helpers can perform driver and/or source specific checks which are > > > also > > > @@ -507,22 +516,34 @@ int drm_helper_probe_single_connector_modes(struct > > > drm_connector *connector, > > > mode_flags |= DRM_MODE_FLAG_3D_MASK; > > > > > > list_for_each_entry(mode, &connector->modes, head) { > > > - if (mode->status == MODE_OK) > > > - mode->status = drm_mode_validate_driver(dev, mode); > > > + if (mode->status != MODE_OK) > > > + continue; > > > + > > > + mode->status = drm_mode_validate_driver(dev, mode); > > > + if (mode->status != MODE_OK) > > > + continue; > > > > > > - if (mode->status == MODE_OK) > > > - mode->status = drm_mode_validate_size(mode, maxX, maxY); > > > + mode->status = drm_mode_validate_size(mode, maxX, maxY); > > > + if (mode->status != MODE_OK) > > > + continue; > > > > > > - if (mode->status == MODE_OK) > > > - mode->status = drm_mode_validate_flag(mode, mode_flags); > > > + mode->status = drm_mode_validate_flag(mode, mode_flags); > > > + if (mode->status != MODE_OK) > > > + continue; > > > > > > - if (mode->status == MODE_OK) > > > - mode->status = drm_mode_validate_pipeline(mode, > > > - connector); > > > + ret = drm_mode_validate_pipeline(mode, connector, &ctx); > > > + if (ret == -EDEADLK) { > > > + drm_modeset_backoff(&ctx); > > > + goto retry; > > > + } else if (WARN_ON_ONCE(ret < 0)) { > > > + mode->status = MODE_BAD; > > This check is wrong actually. We define negative values for drm_mode_status > (MODE_BAD, MODE_ERROR, MODE_STALE) which, at least with how drivers currently > seem to use them, are something we want to treat as not-unexpected errors and > not WARN_ON. Ah, yes, missed that. > This is a bit annoying because it does mean there's some overlap between > drm_mode_status and some legitimate errno values (EPERM, ENOENT, ESRCH). Luckily > I can't see any reason why drivers would want to return those, but I think we > should probably print a debugging message when we get any errno values just so > developers don't get confused (also going to add a IS_ERR() equivalent for > drm_mode_status, but with a different name) Maybe I'm missing something, but having negative values in drm_mode_status doesn't make sense to me, as all the non-zero values there just mean the mode is incorrect for some reason and should be pruned. Would it make sense to better separate the mode-status value and any error return value from mode_valid_ctx(), by adding a drm_mode_status * parameter to the hook and drm_mode_validate_pipeline()? > > > > + } else { > > > + mode->status = ret; > > > + } > > > > > > - if (mode->status == MODE_OK) > > > - mode->status = drm_mode_validate_ycbcr420(mode, > > > - connector); > > > + if (mode->status != MODE_OK) > > > + continue; > > > + mode->status = drm_mode_validate_ycbcr420(mode, connector); > > > } > > > > > > prune: > > > diff --git a/include/drm/drm_modeset_helper_vtables.h > > > b/include/drm/drm_modeset_helper_vtables.h > > > index 421a30f084631..8f020c3424b2b 100644 > > > --- a/include/drm/drm_modeset_helper_vtables.h > > > +++ b/include/drm/drm_modeset_helper_vtables.h > > > @@ -968,6 +968,47 @@ struct drm_connector_helper_funcs { > > > */ > > > enum drm_mode_status (*mode_valid)(struct drm_connector *connector, > > > struct drm_display_mode *mode); > > > + > > > + /** > > > + * @mode_valid_ctx: > > > + * > > > + * Callback to validate a mode for a connector, irrespective of the > > > + * specific display configuration. > > > + * > > > + * This callback is used by the probe helpers to filter the mode list > > > + * (which is usually derived from the EDID data block from the sink). > > > + * See e.g. drm_helper_probe_single_connector_modes(). > > > + * > > > + * This function is optional, and is the atomic version of > > > + * &drm_connector_funcs.mode_valid. > > > + * > > > + * To allow for accessing the atomic state of modesetting objects, the > > > + * helper libraries always call this with ctx set to a valid context, > > > + * and &drm_mode_config.connection_mutex will always be locked with > > > + * the ctx parameter set to @ctx. This allows for taking additional > > > + * locks as required. > > > + * > > > + * Even though additional locks may be acquired, this callback is > > > + * still expected not to take any constraints into account which would > > > + * be influenced by the currently set display state - such constraints > > > + * should be handled in the driver's atomic check. For example, if a > > > + * connector shares display bandwidth with other connectors then it > > > + * would be ok to validate a mode uses against the maximum possible > > ^mode against? > > > > Reviewed-by: Imre Deak <imre.deak@intel.com> > > > > > + * bandwidth of the connector. But it wouldn't be ok to take the > > > + * current bandwidth usage of other connectors into account, as this > > > + * would change depending on the display state. > > > + * > > > + * Returns: > > > + * > > > + * Either &drm_mode_status.MODE_OK, one of the failure reasons in > > > + * &enum drm_mode_status, or -EDEADLK if a deadlock would have > > > + * occurred and we need to backoff. > > > + * > > > + */ > > > + int (*mode_valid_ctx)(struct drm_connector *connector, > > > + struct drm_display_mode *mode, > > > + struct drm_modeset_acquire_ctx *ctx); > > > + > > > /** > > > * @best_encoder: > > > * > > > -- > > > 2.26.2 > > > > > > _______________________________________________ > > > dri-devel mailing list > > > dri-devel@lists.freedesktop.org > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel >
On Wed, 2020-07-08 at 21:45 +0300, Imre Deak wrote: > On Wed, Jul 08, 2020 at 01:25:14PM -0400, Lyude Paul wrote: > > JFYI - found an issue with this patch that wouldn't have shown up on i915, > > info > > down below: > > > > On Wed, 2020-07-08 at 01:40 +0300, Imre Deak wrote: > > > Sorry for the delay, the review as I promised: > > > > > > On Tue, May 26, 2020 at 02:23:09PM -0400, Lyude Paul wrote: > > > > This is just an atomic version of mode_valid, which is intended to be > > > > used for situations where a driver might need to check the atomic state > > > > of objects other than the connector itself. One such example is with > > > > MST, where the maximum possible bandwidth on a connector can change > > > > dynamically irregardless of the display configuration. > > > > > > > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > > > Cc: Lee Shawn C <shawn.c.lee@intel.com> > > > > Tested-by: Lee Shawn C <shawn.c.lee@intel.com> > > > > --- > > > > drivers/gpu/drm/drm_crtc_helper_internal.h | 6 +- > > > > drivers/gpu/drm/drm_probe_helper.c | 65 ++++++++++++++-------- > > > > include/drm/drm_modeset_helper_vtables.h | 41 ++++++++++++++ > > > > 3 files changed, 88 insertions(+), 24 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h > > > > b/drivers/gpu/drm/drm_crtc_helper_internal.h > > > > index f0a66ef47e5ad..ca767cba6094d 100644 > > > > --- a/drivers/gpu/drm/drm_crtc_helper_internal.h > > > > +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h > > > > @@ -73,8 +73,10 @@ enum drm_mode_status drm_crtc_mode_valid(struct > > > > drm_crtc > > > > *crtc, > > > > const struct drm_display_mode > > > > *mode); > > > > enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder > > > > *encoder, > > > > const struct > > > > drm_display_mode > > > > *mode); > > > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > > > *connector, > > > > - struct drm_display_mode > > > > *mode); > > > > +enum drm_mode_status > > > > +drm_connector_mode_valid(struct drm_connector *connector, > > > > + struct drm_display_mode *mode, > > > > + struct drm_modeset_acquire_ctx *ctx); > > > > > > > > struct drm_encoder * > > > > drm_connector_get_single_encoder(struct drm_connector *connector); > > > > diff --git a/drivers/gpu/drm/drm_probe_helper.c > > > > b/drivers/gpu/drm/drm_probe_helper.c > > > > index 466dfbba82564..3132784736841 100644 > > > > --- a/drivers/gpu/drm/drm_probe_helper.c > > > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > > > @@ -86,16 +86,17 @@ drm_mode_validate_flag(const struct drm_display_mode > > > > *mode, > > > > return MODE_OK; > > > > } > > > > > > > > -static enum drm_mode_status > > > > +static int > > > > drm_mode_validate_pipeline(struct drm_display_mode *mode, > > > > - struct drm_connector *connector) > > > > + struct drm_connector *connector, > > > > + struct drm_modeset_acquire_ctx *ctx) > > > > { > > > > struct drm_device *dev = connector->dev; > > > > - enum drm_mode_status ret = MODE_OK; > > > > struct drm_encoder *encoder; > > > > + int ret = MODE_OK; > > > > > > > > /* Step 1: Validate against connector */ > > > > - ret = drm_connector_mode_valid(connector, mode); > > > > + ret = drm_connector_mode_valid(connector, mode, ctx); > > > > if (ret != MODE_OK) > > > > return ret; > > > > > > > > @@ -196,16 +197,23 @@ enum drm_mode_status drm_encoder_mode_valid(struct > > > > drm_encoder *encoder, > > > > return encoder_funcs->mode_valid(encoder, mode); > > > > } > > > > > > > > -enum drm_mode_status drm_connector_mode_valid(struct drm_connector > > > > *connector, > > > > - struct drm_display_mode > > > > *mode) > > > > +int > > > > +drm_connector_mode_valid(struct drm_connector *connector, > > > > + struct drm_display_mode *mode, > > > > + struct drm_modeset_acquire_ctx *ctx) > > > > { > > > > const struct drm_connector_helper_funcs *connector_funcs = > > > > connector->helper_private; > > > > > > > > - if (!connector_funcs || !connector_funcs->mode_valid) > > > > + if (!connector_funcs) > > > > return MODE_OK; > > > > > > > > - return connector_funcs->mode_valid(connector, mode); > > > > + if (connector_funcs->mode_valid_ctx) > > > > + return connector_funcs->mode_valid_ctx(connector, mode, > > > > ctx); > > > > + else if (connector_funcs->mode_valid) > > > > + return connector_funcs->mode_valid(connector, mode); > > > > + else > > > > + return MODE_OK; > > > > } > > > > > > > > #define DRM_OUTPUT_POLL_PERIOD (10*HZ) > > > > @@ -375,8 +383,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); > > > > * (if specified) > > > > * - drm_mode_validate_flag() checks the modes against basic > > > > connector > > > > * capabilities > > > > (interlace_allowed,doublescan_allowed,stereo_allowed) > > > > - * - the optional &drm_connector_helper_funcs.mode_valid helper can > > > > perform > > > > - * driver and/or sink specific checks > > > > + * - the optional &drm_connector_helper_funcs.mode_valid or > > > > + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform > > > > driver > > > > + * and/or sink specific checks > > > > * - the optional &drm_crtc_helper_funcs.mode_valid, > > > > * &drm_bridge_funcs.mode_valid and > > > > &drm_encoder_helper_funcs.mode_valid > > > > * helpers can perform driver and/or source specific checks which > > > > are > > > > also > > > > @@ -507,22 +516,34 @@ int drm_helper_probe_single_connector_modes(struct > > > > drm_connector *connector, > > > > mode_flags |= DRM_MODE_FLAG_3D_MASK; > > > > > > > > list_for_each_entry(mode, &connector->modes, head) { > > > > - if (mode->status == MODE_OK) > > > > - mode->status = drm_mode_validate_driver(dev, > > > > mode); > > > > + if (mode->status != MODE_OK) > > > > + continue; > > > > + > > > > + mode->status = drm_mode_validate_driver(dev, mode); > > > > + if (mode->status != MODE_OK) > > > > + continue; > > > > > > > > - if (mode->status == MODE_OK) > > > > - mode->status = drm_mode_validate_size(mode, > > > > maxX, maxY); > > > > + mode->status = drm_mode_validate_size(mode, maxX, maxY); > > > > + if (mode->status != MODE_OK) > > > > + continue; > > > > > > > > - if (mode->status == MODE_OK) > > > > - mode->status = drm_mode_validate_flag(mode, > > > > mode_flags); > > > > + mode->status = drm_mode_validate_flag(mode, mode_flags); > > > > + if (mode->status != MODE_OK) > > > > + continue; > > > > > > > > - if (mode->status == MODE_OK) > > > > - mode->status = drm_mode_validate_pipeline(mode, > > > > - connec > > > > tor); > > > > + ret = drm_mode_validate_pipeline(mode, connector, &ctx); > > > > + if (ret == -EDEADLK) { > > > > + drm_modeset_backoff(&ctx); > > > > + goto retry; > > > > + } else if (WARN_ON_ONCE(ret < 0)) { > > > > + mode->status = MODE_BAD; > > > > This check is wrong actually. We define negative values for drm_mode_status > > (MODE_BAD, MODE_ERROR, MODE_STALE) which, at least with how drivers > > currently > > seem to use them, are something we want to treat as not-unexpected errors > > and > > not WARN_ON. > > Ah, yes, missed that. > > > This is a bit annoying because it does mean there's some overlap between > > drm_mode_status and some legitimate errno values (EPERM, ENOENT, ESRCH). > > Luckily > > I can't see any reason why drivers would want to return those, but I think > > we > > should probably print a debugging message when we get any errno values just > > so > > developers don't get confused (also going to add a IS_ERR() equivalent for > > drm_mode_status, but with a different name) > > Maybe I'm missing something, but having negative values in > drm_mode_status doesn't make sense to me, as all the non-zero values > there just mean the mode is incorrect for some reason and should be > pruned. > > Would it make sense to better separate the mode-status value and any > error return value from mode_valid_ctx(), by adding a drm_mode_status * > parameter to the hook and drm_mode_validate_pipeline()? yeah-that would probably make more sense. I will go ahead and do that > > > > > + } else { > > > > + mode->status = ret; > > > > + } > > > > > > > > - if (mode->status == MODE_OK) > > > > - mode->status = drm_mode_validate_ycbcr420(mode, > > > > - connec > > > > tor); > > > > + if (mode->status != MODE_OK) > > > > + continue; > > > > + mode->status = drm_mode_validate_ycbcr420(mode, > > > > connector); > > > > } > > > > > > > > prune: > > > > diff --git a/include/drm/drm_modeset_helper_vtables.h > > > > b/include/drm/drm_modeset_helper_vtables.h > > > > index 421a30f084631..8f020c3424b2b 100644 > > > > --- a/include/drm/drm_modeset_helper_vtables.h > > > > +++ b/include/drm/drm_modeset_helper_vtables.h > > > > @@ -968,6 +968,47 @@ struct drm_connector_helper_funcs { > > > > */ > > > > enum drm_mode_status (*mode_valid)(struct drm_connector > > > > *connector, > > > > struct drm_display_mode > > > > *mode); > > > > + > > > > + /** > > > > + * @mode_valid_ctx: > > > > + * > > > > + * Callback to validate a mode for a connector, irrespective of > > > > the > > > > + * specific display configuration. > > > > + * > > > > + * This callback is used by the probe helpers to filter the mode > > > > list > > > > + * (which is usually derived from the EDID data block from the > > > > sink). > > > > + * See e.g. drm_helper_probe_single_connector_modes(). > > > > + * > > > > + * This function is optional, and is the atomic version of > > > > + * &drm_connector_funcs.mode_valid. > > > > + * > > > > + * To allow for accessing the atomic state of modesetting > > > > objects, the > > > > + * helper libraries always call this with ctx set to a valid > > > > context, > > > > + * and &drm_mode_config.connection_mutex will always be locked > > > > with > > > > + * the ctx parameter set to @ctx. This allows for taking > > > > additional > > > > + * locks as required. > > > > + * > > > > + * Even though additional locks may be acquired, this callback > > > > is > > > > + * still expected not to take any constraints into account which > > > > would > > > > + * be influenced by the currently set display state - such > > > > constraints > > > > + * should be handled in the driver's atomic check. For example, > > > > if a > > > > + * connector shares display bandwidth with other connectors then > > > > it > > > > + * would be ok to validate a mode uses against the maximum > > > > possible > > > ^mode against? > > > > > > Reviewed-by: Imre Deak <imre.deak@intel.com> > > > > > > > + * bandwidth of the connector. But it wouldn't be ok to take the > > > > + * current bandwidth usage of other connectors into account, as > > > > this > > > > + * would change depending on the display state. > > > > + * > > > > + * Returns: > > > > + * > > > > + * Either &drm_mode_status.MODE_OK, one of the failure reasons > > > > in > > > > + * &enum drm_mode_status, or -EDEADLK if a deadlock would have > > > > + * occurred and we need to backoff. > > > > + * > > > > + */ > > > > + int (*mode_valid_ctx)(struct drm_connector *connector, > > > > + struct drm_display_mode *mode, > > > > + struct drm_modeset_acquire_ctx *ctx); > > > > + > > > > /** > > > > * @best_encoder: > > > > * > > > > -- > > > > 2.26.2 > > > > > > > > _______________________________________________ > > > > dri-devel mailing list > > > > dri-devel@lists.freedesktop.org > > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/gpu/drm/drm_crtc_helper_internal.h b/drivers/gpu/drm/drm_crtc_helper_internal.h index f0a66ef47e5ad..ca767cba6094d 100644 --- a/drivers/gpu/drm/drm_crtc_helper_internal.h +++ b/drivers/gpu/drm/drm_crtc_helper_internal.h @@ -73,8 +73,10 @@ enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode *mode); enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, const struct drm_display_mode *mode); -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, - struct drm_display_mode *mode); +enum drm_mode_status +drm_connector_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx); struct drm_encoder * drm_connector_get_single_encoder(struct drm_connector *connector); diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 466dfbba82564..3132784736841 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -86,16 +86,17 @@ drm_mode_validate_flag(const struct drm_display_mode *mode, return MODE_OK; } -static enum drm_mode_status +static int drm_mode_validate_pipeline(struct drm_display_mode *mode, - struct drm_connector *connector) + struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx) { struct drm_device *dev = connector->dev; - enum drm_mode_status ret = MODE_OK; struct drm_encoder *encoder; + int ret = MODE_OK; /* Step 1: Validate against connector */ - ret = drm_connector_mode_valid(connector, mode); + ret = drm_connector_mode_valid(connector, mode, ctx); if (ret != MODE_OK) return ret; @@ -196,16 +197,23 @@ enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, return encoder_funcs->mode_valid(encoder, mode); } -enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, - struct drm_display_mode *mode) +int +drm_connector_mode_valid(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx) { const struct drm_connector_helper_funcs *connector_funcs = connector->helper_private; - if (!connector_funcs || !connector_funcs->mode_valid) + if (!connector_funcs) return MODE_OK; - return connector_funcs->mode_valid(connector, mode); + if (connector_funcs->mode_valid_ctx) + return connector_funcs->mode_valid_ctx(connector, mode, ctx); + else if (connector_funcs->mode_valid) + return connector_funcs->mode_valid(connector, mode); + else + return MODE_OK; } #define DRM_OUTPUT_POLL_PERIOD (10*HZ) @@ -375,8 +383,9 @@ EXPORT_SYMBOL(drm_helper_probe_detect); * (if specified) * - drm_mode_validate_flag() checks the modes against basic connector * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) - * - the optional &drm_connector_helper_funcs.mode_valid helper can perform - * driver and/or sink specific checks + * - the optional &drm_connector_helper_funcs.mode_valid or + * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver + * and/or sink specific checks * - the optional &drm_crtc_helper_funcs.mode_valid, * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid * helpers can perform driver and/or source specific checks which are also @@ -507,22 +516,34 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector, mode_flags |= DRM_MODE_FLAG_3D_MASK; list_for_each_entry(mode, &connector->modes, head) { - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_driver(dev, mode); + if (mode->status != MODE_OK) + continue; + + mode->status = drm_mode_validate_driver(dev, mode); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_size(mode, maxX, maxY); + mode->status = drm_mode_validate_size(mode, maxX, maxY); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_flag(mode, mode_flags); + mode->status = drm_mode_validate_flag(mode, mode_flags); + if (mode->status != MODE_OK) + continue; - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_pipeline(mode, - connector); + ret = drm_mode_validate_pipeline(mode, connector, &ctx); + if (ret == -EDEADLK) { + drm_modeset_backoff(&ctx); + goto retry; + } else if (WARN_ON_ONCE(ret < 0)) { + mode->status = MODE_BAD; + } else { + mode->status = ret; + } - if (mode->status == MODE_OK) - mode->status = drm_mode_validate_ycbcr420(mode, - connector); + if (mode->status != MODE_OK) + continue; + mode->status = drm_mode_validate_ycbcr420(mode, connector); } prune: diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 421a30f084631..8f020c3424b2b 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -968,6 +968,47 @@ struct drm_connector_helper_funcs { */ enum drm_mode_status (*mode_valid)(struct drm_connector *connector, struct drm_display_mode *mode); + + /** + * @mode_valid_ctx: + * + * Callback to validate a mode for a connector, irrespective of the + * specific display configuration. + * + * This callback is used by the probe helpers to filter the mode list + * (which is usually derived from the EDID data block from the sink). + * See e.g. drm_helper_probe_single_connector_modes(). + * + * This function is optional, and is the atomic version of + * &drm_connector_funcs.mode_valid. + * + * To allow for accessing the atomic state of modesetting objects, the + * helper libraries always call this with ctx set to a valid context, + * and &drm_mode_config.connection_mutex will always be locked with + * the ctx parameter set to @ctx. This allows for taking additional + * locks as required. + * + * Even though additional locks may be acquired, this callback is + * still expected not to take any constraints into account which would + * be influenced by the currently set display state - such constraints + * should be handled in the driver's atomic check. For example, if a + * connector shares display bandwidth with other connectors then it + * would be ok to validate a mode uses against the maximum possible + * bandwidth of the connector. But it wouldn't be ok to take the + * current bandwidth usage of other connectors into account, as this + * would change depending on the display state. + * + * Returns: + * + * Either &drm_mode_status.MODE_OK, one of the failure reasons in + * &enum drm_mode_status, or -EDEADLK if a deadlock would have + * occurred and we need to backoff. + * + */ + int (*mode_valid_ctx)(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx); + /** * @best_encoder: *