| Message ID | 20231123032615.3760488-1-victor.liu@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: panel: Check device dependency before managing device link | expand |
On Thu, Nov 23, 2023 at 4:22 AM Liu Ying <victor.liu@nxp.com> wrote: > Some panel devices already depend on DRM device, like the panel in > arch/arm/boot/dts/st/ste-ux500-samsung-skomer.dts, because DRM device is > the ancestor of those panel devices. device_link_add() would fail by > returning a NULL pointer for those panel devices because of the existing > dependency. So, check the dependency by calling device_is_dependent() > before adding or deleting device link between panel device and DRM device > so that the link is managed only for independent panel devices. > > Fixes: 887878014534 ("drm/bridge: panel: Fix device link for DRM_BRIDGE_ATTACH_NO_CONNECTOR") > Fixes: 199cf07ebd2b ("drm/bridge: panel: Add a device link between drm device and panel device") > Reported-by: Linus Walleij <linus.walleij@linaro.org> > Closes: https://lore.kernel.org/lkml/CACRpkdaGzXD6HbiX7mVUNJAJtMEPG00Pp6+nJ1P0JrfJ-ArMvQ@mail.gmail.com/T/ > Tested-by: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Liu Ying <victor.liu@nxp.com> Patch applied to drm-misc-fixes. Yours, Linus Walleij
On Thu, Nov 23, 2023 at 11:26:15AM +0800, Liu Ying wrote: > Some panel devices already depend on DRM device, like the panel in > arch/arm/boot/dts/st/ste-ux500-samsung-skomer.dts, because DRM device is > the ancestor of those panel devices. device_link_add() would fail by > returning a NULL pointer for those panel devices because of the existing > dependency. So, check the dependency by calling device_is_dependent() > before adding or deleting device link between panel device and DRM device > so that the link is managed only for independent panel devices. > > Fixes: 887878014534 ("drm/bridge: panel: Fix device link for DRM_BRIDGE_ATTACH_NO_CONNECTOR") > Fixes: 199cf07ebd2b ("drm/bridge: panel: Add a device link between drm device and panel device") > Reported-by: Linus Walleij <linus.walleij@linaro.org> > Closes: https://lore.kernel.org/lkml/CACRpkdaGzXD6HbiX7mVUNJAJtMEPG00Pp6+nJ1P0JrfJ-ArMvQ@mail.gmail.com/T/ > Tested-by: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Liu Ying <victor.liu@nxp.com> > --- > drivers/gpu/drm/bridge/panel.c | 27 ++++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c > index e48823a4f1ed..5e8980023407 100644 > --- a/drivers/gpu/drm/bridge/panel.c > +++ b/drivers/gpu/drm/bridge/panel.c > @@ -23,6 +23,7 @@ struct panel_bridge { > struct drm_panel *panel; > struct device_link *link; > u32 connector_type; > + bool is_independent; > }; > > static inline struct panel_bridge * > @@ -67,12 +68,17 @@ static int panel_bridge_attach(struct drm_bridge *bridge, > struct drm_device *drm_dev = bridge->dev; > int ret; > > - panel_bridge->link = device_link_add(drm_dev->dev, panel->dev, > - DL_FLAG_STATELESS); > - if (!panel_bridge->link) { > - DRM_ERROR("Failed to add device link between %s and %s\n", > - dev_name(drm_dev->dev), dev_name(panel->dev)); > - return -EINVAL; > + panel_bridge->is_independent = !device_is_dependent(drm_dev->dev, > + panel->dev); This broke the build. Looks like device_is_dependent() is not even exported. ERROR: modpost: "device_is_dependent" [drivers/gpu/drm/drm_kms_helper.ko] undefined! The recommended defconfigs in rerere-cache do seem to have CONFIG_DRM_KMS_HELPER=m so this should have been caught before pushing. How did it slip through? > + > + if (panel_bridge->is_independent) { > + panel_bridge->link = device_link_add(drm_dev->dev, panel->dev, > + DL_FLAG_STATELESS); > + if (!panel_bridge->link) { > + DRM_ERROR("Failed to add device link between %s and %s\n", > + dev_name(drm_dev->dev), dev_name(panel->dev)); > + return -EINVAL; > + } > } > > if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) > @@ -80,7 +86,8 @@ static int panel_bridge_attach(struct drm_bridge *bridge, > > if (!bridge->encoder) { > DRM_ERROR("Missing encoder\n"); > - device_link_del(panel_bridge->link); > + if (panel_bridge->is_independent) > + device_link_del(panel_bridge->link); > return -ENODEV; > } > > @@ -92,7 +99,8 @@ static int panel_bridge_attach(struct drm_bridge *bridge, > panel_bridge->connector_type); > if (ret) { > DRM_ERROR("Failed to initialize connector\n"); > - device_link_del(panel_bridge->link); > + if (panel_bridge->is_independent) > + device_link_del(panel_bridge->link); > return ret; > } > > @@ -115,7 +123,8 @@ static void panel_bridge_detach(struct drm_bridge *bridge) > struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); > struct drm_connector *connector = &panel_bridge->connector; > > - device_link_del(panel_bridge->link); > + if (panel_bridge->is_independent) > + device_link_del(panel_bridge->link); > > /* > * Cleanup the connector if we know it was initialized. > -- > 2.37.1
On Mon, Nov 27, 2023 at 2:36 PM Ville Syrjälä <ville.syrjala@linux.intel.com> wrote: > > + panel_bridge->is_independent = !device_is_dependent(drm_dev->dev, > > + panel->dev); > > This broke the build. Looks like device_is_dependent() is not even exported. > ERROR: modpost: "device_is_dependent" [drivers/gpu/drm/drm_kms_helper.ko] undefined! Yep Ying made a fix, I just applied and pushed it because it was obviously correct. > The recommended defconfigs in rerere-cache do seem to have CONFIG_DRM_KMS_HELPER=m > so this should have been caught before pushing. How did it slip through? My neglect. Neglect may have something to do with my desktop being 10 years+ old. Building random defconfigs on this machine takes so long time that invariably other stuff has been pushed to the branch before the compiles even complete. Yeah I know. I should buy a better computer. Yours, Linus Walleij
diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c index e48823a4f1ed..5e8980023407 100644 --- a/drivers/gpu/drm/bridge/panel.c +++ b/drivers/gpu/drm/bridge/panel.c @@ -23,6 +23,7 @@ struct panel_bridge { struct drm_panel *panel; struct device_link *link; u32 connector_type; + bool is_independent; }; static inline struct panel_bridge * @@ -67,12 +68,17 @@ static int panel_bridge_attach(struct drm_bridge *bridge, struct drm_device *drm_dev = bridge->dev; int ret; - panel_bridge->link = device_link_add(drm_dev->dev, panel->dev, - DL_FLAG_STATELESS); - if (!panel_bridge->link) { - DRM_ERROR("Failed to add device link between %s and %s\n", - dev_name(drm_dev->dev), dev_name(panel->dev)); - return -EINVAL; + panel_bridge->is_independent = !device_is_dependent(drm_dev->dev, + panel->dev); + + if (panel_bridge->is_independent) { + panel_bridge->link = device_link_add(drm_dev->dev, panel->dev, + DL_FLAG_STATELESS); + if (!panel_bridge->link) { + DRM_ERROR("Failed to add device link between %s and %s\n", + dev_name(drm_dev->dev), dev_name(panel->dev)); + return -EINVAL; + } } if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) @@ -80,7 +86,8 @@ static int panel_bridge_attach(struct drm_bridge *bridge, if (!bridge->encoder) { DRM_ERROR("Missing encoder\n"); - device_link_del(panel_bridge->link); + if (panel_bridge->is_independent) + device_link_del(panel_bridge->link); return -ENODEV; } @@ -92,7 +99,8 @@ static int panel_bridge_attach(struct drm_bridge *bridge, panel_bridge->connector_type); if (ret) { DRM_ERROR("Failed to initialize connector\n"); - device_link_del(panel_bridge->link); + if (panel_bridge->is_independent) + device_link_del(panel_bridge->link); return ret; } @@ -115,7 +123,8 @@ static void panel_bridge_detach(struct drm_bridge *bridge) struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); struct drm_connector *connector = &panel_bridge->connector; - device_link_del(panel_bridge->link); + if (panel_bridge->is_independent) + device_link_del(panel_bridge->link); /* * Cleanup the connector if we know it was initialized.
Some panel devices already depend on DRM device, like the panel in arch/arm/boot/dts/st/ste-ux500-samsung-skomer.dts, because DRM device is the ancestor of those panel devices. device_link_add() would fail by returning a NULL pointer for those panel devices because of the existing dependency. So, check the dependency by calling device_is_dependent() before adding or deleting device link between panel device and DRM device so that the link is managed only for independent panel devices. Fixes: 887878014534 ("drm/bridge: panel: Fix device link for DRM_BRIDGE_ATTACH_NO_CONNECTOR") Fixes: 199cf07ebd2b ("drm/bridge: panel: Add a device link between drm device and panel device") Reported-by: Linus Walleij <linus.walleij@linaro.org> Closes: https://lore.kernel.org/lkml/CACRpkdaGzXD6HbiX7mVUNJAJtMEPG00Pp6+nJ1P0JrfJ-ArMvQ@mail.gmail.com/T/ Tested-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Liu Ying <victor.liu@nxp.com> --- drivers/gpu/drm/bridge/panel.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)