Message ID | 20180917174344.22011-1-lyude@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | drm/probe_helper: Don't bother probing when connectors are forced off | expand |
On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > Userspace asked them to be forced off, so why would we care about what a > probe tells us? I believe there should be force checks in the callers already. Or are we missing some? > > Signed-off-by: Lyude Paul <lyude@redhat.com> > --- > drivers/gpu/drm/drm_probe_helper.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index a1bb157bfdfa..56d2b5dd1f58 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -269,7 +269,9 @@ drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force) > retry: > ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx); > if (!ret) { > - if (funcs->detect_ctx) > + if (connector->force == DRM_FORCE_OFF) > + ret = connector_status_disconnected; connector->force is protected by mode_config.mutex IIRC. > + else if (funcs->detect_ctx) > ret = funcs->detect_ctx(connector, &ctx, force); > else if (connector->funcs->detect) > ret = connector->funcs->detect(connector, force); > @@ -317,6 +319,9 @@ drm_helper_probe_detect(struct drm_connector *connector, > if (ret) > return ret; > > + if (connector->force == DRM_FORCE_OFF) > + return connector_status_disconnected; > + > if (funcs->detect_ctx) > return funcs->detect_ctx(connector, ctx, force); > else if (connector->funcs->detect) > -- > 2.17.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > Userspace asked them to be forced off, so why would we care about what a > > probe tells us? > > I believe there should be force checks in the callers already. > Or are we missing some? JFYI, this is to fix "DDC responded but no EDID" errors from nouveau, which presumably come from the fact that having a connector forced off disables reading it's EDID. It's possible we are missing something in nouveau_connector_detect(), but I'm confused as to why we would want to call ->probe() at all in the first place > > > > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > --- > > drivers/gpu/drm/drm_probe_helper.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/drm_probe_helper.c > > b/drivers/gpu/drm/drm_probe_helper.c > > index a1bb157bfdfa..56d2b5dd1f58 100644 > > --- a/drivers/gpu/drm/drm_probe_helper.c > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > @@ -269,7 +269,9 @@ drm_helper_probe_detect_ctx(struct drm_connector > > *connector, bool force) > > retry: > > ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, > > &ctx); > > if (!ret) { > > - if (funcs->detect_ctx) > > + if (connector->force == DRM_FORCE_OFF) > > + ret = connector_status_disconnected; > > connector->force is protected by mode_config.mutex IIRC. > > > + else if (funcs->detect_ctx) > > ret = funcs->detect_ctx(connector, &ctx, force); > > else if (connector->funcs->detect) > > ret = connector->funcs->detect(connector, force); > > @@ -317,6 +319,9 @@ drm_helper_probe_detect(struct drm_connector *connector, > > if (ret) > > return ret; > > > > + if (connector->force == DRM_FORCE_OFF) > > + return connector_status_disconnected; > > + > > if (funcs->detect_ctx) > > return funcs->detect_ctx(connector, ctx, force); > > else if (connector->funcs->detect) > > -- > > 2.17.1 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > >
On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > Userspace asked them to be forced off, so why would we care about what a > > probe tells us? > > I believe there should be force checks in the callers already. > Or are we missing some? JFYI, what triggered me to send this patch are these error messages that come from nouveau when a hotplug happens on a port that we've forced off: [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP-2 [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] [CONNECTOR:61:DP-2] status updated from disconnected to disconnected That being said; I'm sure there are probably some checks missing, but I don't really see the purpose in calling the driver's probe functions at all if they're just supposed to return the status we forced. > > > > > Signed-off-by: Lyude Paul <lyude@redhat.com> > > --- > > drivers/gpu/drm/drm_probe_helper.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/drm_probe_helper.c > > b/drivers/gpu/drm/drm_probe_helper.c > > index a1bb157bfdfa..56d2b5dd1f58 100644 > > --- a/drivers/gpu/drm/drm_probe_helper.c > > +++ b/drivers/gpu/drm/drm_probe_helper.c > > @@ -269,7 +269,9 @@ drm_helper_probe_detect_ctx(struct drm_connector > > *connector, bool force) > > retry: > > ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, > > &ctx); > > if (!ret) { > > - if (funcs->detect_ctx) > > + if (connector->force == DRM_FORCE_OFF) > > + ret = connector_status_disconnected; > > connector->force is protected by mode_config.mutex IIRC. > > > + else if (funcs->detect_ctx) > > ret = funcs->detect_ctx(connector, &ctx, force); > > else if (connector->funcs->detect) > > ret = connector->funcs->detect(connector, force); > > @@ -317,6 +319,9 @@ drm_helper_probe_detect(struct drm_connector *connector, > > if (ret) > > return ret; > > > > + if (connector->force == DRM_FORCE_OFF) > > + return connector_status_disconnected; > > + > > if (funcs->detect_ctx) > > return funcs->detect_ctx(connector, ctx, force); > > else if (connector->funcs->detect) > > -- > > 2.17.1 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > >
On Mon, Sep 17, 2018 at 02:10:02PM -0400, Lyude Paul wrote: > On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > > Userspace asked them to be forced off, so why would we care about what a > > > probe tells us? > > > > I believe there should be force checks in the callers already. > > Or are we missing some? > > JFYI, what triggered me to send this patch are these error messages that come > from nouveau when a hotplug happens on a port that we've forced off: > > [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP-2 > [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] [CONNECTOR:61:DP-2] status updated from disconnected to disconnected > > That being said; I'm sure there are probably some checks missing, but I don't > really see the purpose in calling the driver's probe functions at all if they're > just supposed to return the status we forced. Digging through my cobweb ridden local git repository I found this: commit bbd17813a7c7d0210c619365707044d0fb29e3f0 Author: Ville Syrjälä <ville.syrjala@linux.intel.com> Date: Mon Jun 10 15:28:55 2013 +0300 drm: Ignore forced connectors in drm_helper_hpd_irq_event() drm_helper_hpd_irq_event() calls the connector's .detect() function even for forced connectors. If the returned status doesn't match the forced status, we will send the hotplug event, causing userspace to re-probe all the connectors. Eventually we should end up back where we started when drm_helper_probe_single_connector_modes() overwrites the connector status with the forced status. We can avoid all that pointles work if we just skip forced connectors in drm_helper_hpd_irq_event(). Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index ed1334e27c33..4fc2ad76c107 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -1086,6 +1086,10 @@ void drm_helper_hpd_irq_event(struct drm_device *dev) mutex_lock(&dev->mode_config.mutex); list_for_each_entry(connector, &dev->mode_config.connector_list, head) { + /* Ignore forced connectors. */ + if (connector->force) + continue; + /* Only handle HPD capable connectors. */ if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) continue; I guess I never sent it out.
On Mon, 2018-09-17 at 21:16 +0300, Ville Syrjälä wrote: > On Mon, Sep 17, 2018 at 02:10:02PM -0400, Lyude Paul wrote: > > On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > > > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > > > Userspace asked them to be forced off, so why would we care about what a > > > > probe tells us? > > > > > > I believe there should be force checks in the callers already. > > > Or are we missing some? > > > > JFYI, what triggered me to send this patch are these error messages that > > come > > from nouveau when a hotplug happens on a port that we've forced off: > > > > [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP- > > 2 > > [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] > > [CONNECTOR:61:DP-2] status updated from disconnected to disconnected > > > > That being said; I'm sure there are probably some checks missing, but I > > don't > > really see the purpose in calling the driver's probe functions at all if > > they're > > just supposed to return the status we forced. > > Digging through my cobweb ridden local git repository I found this: > > commit bbd17813a7c7d0210c619365707044d0fb29e3f0 > Author: Ville Syrjälä <ville.syrjala@linux.intel.com> > Date: Mon Jun 10 15:28:55 2013 +0300 > > drm: Ignore forced connectors in drm_helper_hpd_irq_event() > > drm_helper_hpd_irq_event() calls the connector's .detect() function > even for forced connectors. If the returned status doesn't match the > forced status, we will send the hotplug event, causing userspace to > re-probe all the connectors. Eventually we should end up back where > we started when drm_helper_probe_single_connector_modes() overwrites > the connector status with the forced status. > > We can avoid all that pointles work if we just skip forced connectors > in drm_helper_hpd_irq_event(). > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c > b/drivers/gpu/drm/drm_crtc_helper.c > index ed1334e27c33..4fc2ad76c107 100644 > --- a/drivers/gpu/drm/drm_crtc_helper.c > +++ b/drivers/gpu/drm/drm_crtc_helper.c > @@ -1086,6 +1086,10 @@ void drm_helper_hpd_irq_event(struct drm_device *dev) > mutex_lock(&dev->mode_config.mutex); > list_for_each_entry(connector, &dev->mode_config.connector_list, head) { > > + /* Ignore forced connectors. */ > + if (connector->force) > + continue; > + > /* Only handle HPD capable connectors. */ > if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) > continue; > > > I guess I never sent it out. Ahhh, to be honest though this patch isn't really enough. drm_helper_hpd_irq_event() isn't going to be used by all drivers (I may remove some usage of it in nouveau in the near future, even) so I still think it would be a better idea to just add this into drm_helper_probe_detect() and drm_helper_probe_detect_ctx() so everything gets covered >
On Mon, Sep 17, 2018 at 05:12:04PM -0400, Lyude Paul wrote: > On Mon, 2018-09-17 at 21:16 +0300, Ville Syrjälä wrote: > > On Mon, Sep 17, 2018 at 02:10:02PM -0400, Lyude Paul wrote: > > > On Mon, 2018-09-17 at 20:55 +0300, Ville Syrjälä wrote: > > > > On Mon, Sep 17, 2018 at 01:43:44PM -0400, Lyude Paul wrote: > > > > > Userspace asked them to be forced off, so why would we care about what a > > > > > probe tells us? > > > > > > > > I believe there should be force checks in the callers already. > > > > Or are we missing some? > > > > > > JFYI, what triggered me to send this patch are these error messages that > > > come > > > from nouveau when a hotplug happens on a port that we've forced off: > > > > > > [ 1903.918104] nouveau 0000:01:00.0: DRM: DDC responded, but no EDID for DP- > > > 2 > > > [ 1903.918123] [drm:drm_helper_hpd_irq_event [drm_kms_helper]] > > > [CONNECTOR:61:DP-2] status updated from disconnected to disconnected > > > > > > That being said; I'm sure there are probably some checks missing, but I > > > don't > > > really see the purpose in calling the driver's probe functions at all if > > > they're > > > just supposed to return the status we forced. > > > > Digging through my cobweb ridden local git repository I found this: > > > > commit bbd17813a7c7d0210c619365707044d0fb29e3f0 > > Author: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Date: Mon Jun 10 15:28:55 2013 +0300 > > > > drm: Ignore forced connectors in drm_helper_hpd_irq_event() > > > > drm_helper_hpd_irq_event() calls the connector's .detect() function > > even for forced connectors. If the returned status doesn't match the > > forced status, we will send the hotplug event, causing userspace to > > re-probe all the connectors. Eventually we should end up back where > > we started when drm_helper_probe_single_connector_modes() overwrites > > the connector status with the forced status. > > > > We can avoid all that pointles work if we just skip forced connectors > > in drm_helper_hpd_irq_event(). > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > diff --git a/drivers/gpu/drm/drm_crtc_helper.c > > b/drivers/gpu/drm/drm_crtc_helper.c > > index ed1334e27c33..4fc2ad76c107 100644 > > --- a/drivers/gpu/drm/drm_crtc_helper.c > > +++ b/drivers/gpu/drm/drm_crtc_helper.c > > @@ -1086,6 +1086,10 @@ void drm_helper_hpd_irq_event(struct drm_device *dev) > > mutex_lock(&dev->mode_config.mutex); > > list_for_each_entry(connector, &dev->mode_config.connector_list, head) { > > > > + /* Ignore forced connectors. */ > > + if (connector->force) > > + continue; > > + > > /* Only handle HPD capable connectors. */ > > if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) > > continue; > > > > > > I guess I never sent it out. > > Ahhh, to be honest though this patch isn't really enough. > drm_helper_hpd_irq_event() isn't going to be used by all drivers (I may remove > some usage of it in nouveau in the near future, even) so I still think it would > be a better idea to just add this into drm_helper_probe_detect() and > drm_helper_probe_detect_ctx() so everything gets covered Atm all connector->force handling is outside of drm_helper_probe_detect. I guess we could try to push (some) of it into this helper, if that's useful. There seems to be some duplication already. But adding a redundant check like you do here feels a bit funky. Maybe makes more sense in context of the nouveau stuff you're working on? -Daniel
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index a1bb157bfdfa..56d2b5dd1f58 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -269,7 +269,9 @@ drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force) retry: ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx); if (!ret) { - if (funcs->detect_ctx) + if (connector->force == DRM_FORCE_OFF) + ret = connector_status_disconnected; + else if (funcs->detect_ctx) ret = funcs->detect_ctx(connector, &ctx, force); else if (connector->funcs->detect) ret = connector->funcs->detect(connector, force); @@ -317,6 +319,9 @@ drm_helper_probe_detect(struct drm_connector *connector, if (ret) return ret; + if (connector->force == DRM_FORCE_OFF) + return connector_status_disconnected; + if (funcs->detect_ctx) return funcs->detect_ctx(connector, ctx, force); else if (connector->funcs->detect)
Userspace asked them to be forced off, so why would we care about what a probe tells us? Signed-off-by: Lyude Paul <lyude@redhat.com> --- drivers/gpu/drm/drm_probe_helper.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)