| Message ID | 20250206-hotplug-drm-bridge-v6-5-9d6f2c9c3058@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for hot-pluggable DRM bridges | expand |
On Thu, Feb 06, 2025 at 07:14:20PM +0100, Luca Ceresoli wrote: > The global bridges_list holding all the bridges between drm_bridge_add() > and drm_bridge_remove() cannot be inspected via debugfs. Add a file showing > it. > > To avoid code duplication, move the code printing a bridge info to a common > function. > > Note: this change requires exporting bridge_list and the mutex protecting > it. > > Also add a comment about bridge_lock to make checkpatch happy. I think, exporting mutex _and_ a list is a bad idea (especially since they don't have a proper prefix). It might be better to make the bridge_print() function a more public one (and name it drm_bridge_print()) and move allbridges attribute definition to drm_bridge.c > > Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> > > --- > > This patch was added in v6. > --- > drivers/gpu/drm/drm_bridge.c | 5 +-- > drivers/gpu/drm/drm_debugfs.c | 70 +++++++++++++++++++++++++++++------------- > drivers/gpu/drm/drm_drv.c | 1 + > drivers/gpu/drm/drm_internal.h | 9 ++++++ > 4 files changed, 61 insertions(+), 24 deletions(-) > > diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c > index 241a384ebce39b4a3db58c208af27960904fc662..87cebec2de806781cee22da54d666eee9bde3648 100644 > --- a/drivers/gpu/drm/drm_bridge.c > +++ b/drivers/gpu/drm/drm_bridge.c > @@ -195,8 +195,9 @@ > * driver. > */ > > -static DEFINE_MUTEX(bridge_lock); > -static LIST_HEAD(bridge_list); > +/* Protect bridge_list */ > +DEFINE_MUTEX(bridge_lock); > +LIST_HEAD(bridge_list); > > /** > * drm_bridge_add - add the given bridge to the global bridge list > diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c > index 6b2178864c7ee12db9aa1f562e106b2f604439f8..7424d5237e7615d63de6bba572ee6050da6709d0 100644 > --- a/drivers/gpu/drm/drm_debugfs.c > +++ b/drivers/gpu/drm/drm_debugfs.c > @@ -740,6 +740,30 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc) > crtc->debugfs_entry = NULL; > } > > +static void bridge_print(struct drm_printer *p, struct drm_bridge *bridge, unsigned int idx) > +{ > + drm_printf(p, "bridge[%u]: %ps\n", idx, bridge->funcs); > + drm_printf(p, "\ttype: [%d] %s\n", > + bridge->type, > + drm_get_connector_type_name(bridge->type)); > + > + if (bridge->of_node) > + drm_printf(p, "\tOF: %pOFfc\n", bridge->of_node); > + > + drm_printf(p, "\tops: [0x%x]", bridge->ops); > + if (bridge->ops & DRM_BRIDGE_OP_DETECT) > + drm_puts(p, " detect"); > + if (bridge->ops & DRM_BRIDGE_OP_EDID) > + drm_puts(p, " edid"); > + if (bridge->ops & DRM_BRIDGE_OP_HPD) > + drm_puts(p, " hpd"); > + if (bridge->ops & DRM_BRIDGE_OP_MODES) > + drm_puts(p, " modes"); > + if (bridge->ops & DRM_BRIDGE_OP_HDMI) > + drm_puts(p, " hdmi"); > + drm_puts(p, "\n"); > +} > + > static int bridges_show(struct seq_file *m, void *data) > { > struct drm_encoder *encoder = m->private; > @@ -747,28 +771,8 @@ static int bridges_show(struct seq_file *m, void *data) > struct drm_bridge *bridge; > unsigned int idx = 0; > > - drm_for_each_bridge_in_chain(encoder, bridge) { > - drm_printf(&p, "bridge[%u]: %ps\n", idx++, bridge->funcs); > - drm_printf(&p, "\ttype: [%d] %s\n", > - bridge->type, > - drm_get_connector_type_name(bridge->type)); > - > - if (bridge->of_node) > - drm_printf(&p, "\tOF: %pOFfc\n", bridge->of_node); > - > - drm_printf(&p, "\tops: [0x%x]", bridge->ops); > - if (bridge->ops & DRM_BRIDGE_OP_DETECT) > - drm_puts(&p, " detect"); > - if (bridge->ops & DRM_BRIDGE_OP_EDID) > - drm_puts(&p, " edid"); > - if (bridge->ops & DRM_BRIDGE_OP_HPD) > - drm_puts(&p, " hpd"); > - if (bridge->ops & DRM_BRIDGE_OP_MODES) > - drm_puts(&p, " modes"); > - if (bridge->ops & DRM_BRIDGE_OP_HDMI) > - drm_puts(&p, " hdmi"); > - drm_puts(&p, "\n"); > - } > + drm_for_each_bridge_in_chain(encoder, bridge) > + bridge_print(&p, bridge, idx++); > > return 0; > } > @@ -802,3 +806,25 @@ void drm_debugfs_encoder_remove(struct drm_encoder *encoder) > debugfs_remove_recursive(encoder->debugfs_entry); > encoder->debugfs_entry = NULL; > } > + > +static int allbridges_show(struct seq_file *m, void *data) > +{ > + struct drm_printer p = drm_seq_file_printer(m); > + struct drm_bridge *bridge; > + unsigned int idx = 0; > + > + mutex_lock(&bridge_lock); > + > + list_for_each_entry(bridge, &bridge_list, list) > + bridge_print(&p, bridge, idx++); > + > + mutex_unlock(&bridge_lock); > + > + return 0; > +} > +DEFINE_SHOW_ATTRIBUTE(allbridges); Should it be DEFINE_DEBUGFS_ATTRIBUTE instead? > + > +void drm_debugfs_global_add(struct dentry *root) > +{ > + debugfs_create_file("bridges", 0444, root, NULL, &allbridges_fops); > +} > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 3cf440eee8a2ab3de134d925db8f1d2ce68062b7..9b6d7bd16ba409b6a9155a9fecbec6bfdd5ea0c2 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -1120,6 +1120,7 @@ static int __init drm_core_init(void) > } > > drm_debugfs_root = debugfs_create_dir("dri", NULL); > + drm_debugfs_global_add(drm_debugfs_root); > > ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops); > if (ret < 0) > diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h > index b2b6a8e49dda46f1cb3b048ef7b28356dd3aaa4e..b6e875d4b25faae6bb0bb952c3c12bd4819698ec 100644 > --- a/drivers/gpu/drm/drm_internal.h > +++ b/drivers/gpu/drm/drm_internal.h > @@ -48,6 +48,10 @@ struct drm_prime_file_private; > struct drm_printer; > struct drm_vblank_crtc; > > +// for drm_debugfs.c > +extern struct mutex bridge_lock; > +extern struct list_head bridge_list; > + > /* drm_client_event.c */ > #if defined(CONFIG_DRM_CLIENT) > void drm_client_debugfs_init(struct drm_device *dev); > @@ -196,6 +200,7 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc); > void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc); > void drm_debugfs_encoder_add(struct drm_encoder *encoder); > void drm_debugfs_encoder_remove(struct drm_encoder *encoder); > +void drm_debugfs_global_add(struct dentry *drm_debugfs_root); > #else > static inline void drm_debugfs_dev_fini(struct drm_device *dev) > { > @@ -241,6 +246,10 @@ static inline void drm_debugfs_encoder_remove(struct drm_encoder *encoder) > { > } > > +static inline void drm_debugfs_global_add(struct dentry *drm_debugfs_root) > +{ > +} > + > #endif > > drm_ioctl_t drm_version; > > -- > 2.34.1 >
Hi Dmitry, On Fri, 7 Feb 2025 04:41:12 +0200 Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote: > On Thu, Feb 06, 2025 at 07:14:20PM +0100, Luca Ceresoli wrote: > > The global bridges_list holding all the bridges between drm_bridge_add() > > and drm_bridge_remove() cannot be inspected via debugfs. Add a file showing > > it. > > > > To avoid code duplication, move the code printing a bridge info to a common > > function. > > > > Note: this change requires exporting bridge_list and the mutex protecting > > it. > > > > Also add a comment about bridge_lock to make checkpatch happy. > > I think, exporting mutex _and_ a list is a bad idea (especially since > they don't have a proper prefix). It might be better to make the > bridge_print() function a more public one (and name it > drm_bridge_print()) and move allbridges attribute definition to > drm_bridge.c I was also not happy with exporting these two symbols, and agree exporting a print function from drm_bridge.c is cleaner. I'll rearrange this for v7. Luca
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 241a384ebce39b4a3db58c208af27960904fc662..87cebec2de806781cee22da54d666eee9bde3648 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -195,8 +195,9 @@ * driver. */ -static DEFINE_MUTEX(bridge_lock); -static LIST_HEAD(bridge_list); +/* Protect bridge_list */ +DEFINE_MUTEX(bridge_lock); +LIST_HEAD(bridge_list); /** * drm_bridge_add - add the given bridge to the global bridge list diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index 6b2178864c7ee12db9aa1f562e106b2f604439f8..7424d5237e7615d63de6bba572ee6050da6709d0 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -740,6 +740,30 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc) crtc->debugfs_entry = NULL; } +static void bridge_print(struct drm_printer *p, struct drm_bridge *bridge, unsigned int idx) +{ + drm_printf(p, "bridge[%u]: %ps\n", idx, bridge->funcs); + drm_printf(p, "\ttype: [%d] %s\n", + bridge->type, + drm_get_connector_type_name(bridge->type)); + + if (bridge->of_node) + drm_printf(p, "\tOF: %pOFfc\n", bridge->of_node); + + drm_printf(p, "\tops: [0x%x]", bridge->ops); + if (bridge->ops & DRM_BRIDGE_OP_DETECT) + drm_puts(p, " detect"); + if (bridge->ops & DRM_BRIDGE_OP_EDID) + drm_puts(p, " edid"); + if (bridge->ops & DRM_BRIDGE_OP_HPD) + drm_puts(p, " hpd"); + if (bridge->ops & DRM_BRIDGE_OP_MODES) + drm_puts(p, " modes"); + if (bridge->ops & DRM_BRIDGE_OP_HDMI) + drm_puts(p, " hdmi"); + drm_puts(p, "\n"); +} + static int bridges_show(struct seq_file *m, void *data) { struct drm_encoder *encoder = m->private; @@ -747,28 +771,8 @@ static int bridges_show(struct seq_file *m, void *data) struct drm_bridge *bridge; unsigned int idx = 0; - drm_for_each_bridge_in_chain(encoder, bridge) { - drm_printf(&p, "bridge[%u]: %ps\n", idx++, bridge->funcs); - drm_printf(&p, "\ttype: [%d] %s\n", - bridge->type, - drm_get_connector_type_name(bridge->type)); - - if (bridge->of_node) - drm_printf(&p, "\tOF: %pOFfc\n", bridge->of_node); - - drm_printf(&p, "\tops: [0x%x]", bridge->ops); - if (bridge->ops & DRM_BRIDGE_OP_DETECT) - drm_puts(&p, " detect"); - if (bridge->ops & DRM_BRIDGE_OP_EDID) - drm_puts(&p, " edid"); - if (bridge->ops & DRM_BRIDGE_OP_HPD) - drm_puts(&p, " hpd"); - if (bridge->ops & DRM_BRIDGE_OP_MODES) - drm_puts(&p, " modes"); - if (bridge->ops & DRM_BRIDGE_OP_HDMI) - drm_puts(&p, " hdmi"); - drm_puts(&p, "\n"); - } + drm_for_each_bridge_in_chain(encoder, bridge) + bridge_print(&p, bridge, idx++); return 0; } @@ -802,3 +806,25 @@ void drm_debugfs_encoder_remove(struct drm_encoder *encoder) debugfs_remove_recursive(encoder->debugfs_entry); encoder->debugfs_entry = NULL; } + +static int allbridges_show(struct seq_file *m, void *data) +{ + struct drm_printer p = drm_seq_file_printer(m); + struct drm_bridge *bridge; + unsigned int idx = 0; + + mutex_lock(&bridge_lock); + + list_for_each_entry(bridge, &bridge_list, list) + bridge_print(&p, bridge, idx++); + + mutex_unlock(&bridge_lock); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(allbridges); + +void drm_debugfs_global_add(struct dentry *root) +{ + debugfs_create_file("bridges", 0444, root, NULL, &allbridges_fops); +} diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 3cf440eee8a2ab3de134d925db8f1d2ce68062b7..9b6d7bd16ba409b6a9155a9fecbec6bfdd5ea0c2 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -1120,6 +1120,7 @@ static int __init drm_core_init(void) } drm_debugfs_root = debugfs_create_dir("dri", NULL); + drm_debugfs_global_add(drm_debugfs_root); ret = register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops); if (ret < 0) diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index b2b6a8e49dda46f1cb3b048ef7b28356dd3aaa4e..b6e875d4b25faae6bb0bb952c3c12bd4819698ec 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -48,6 +48,10 @@ struct drm_prime_file_private; struct drm_printer; struct drm_vblank_crtc; +// for drm_debugfs.c +extern struct mutex bridge_lock; +extern struct list_head bridge_list; + /* drm_client_event.c */ #if defined(CONFIG_DRM_CLIENT) void drm_client_debugfs_init(struct drm_device *dev); @@ -196,6 +200,7 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc); void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc); void drm_debugfs_encoder_add(struct drm_encoder *encoder); void drm_debugfs_encoder_remove(struct drm_encoder *encoder); +void drm_debugfs_global_add(struct dentry *drm_debugfs_root); #else static inline void drm_debugfs_dev_fini(struct drm_device *dev) { @@ -241,6 +246,10 @@ static inline void drm_debugfs_encoder_remove(struct drm_encoder *encoder) { } +static inline void drm_debugfs_global_add(struct dentry *drm_debugfs_root) +{ +} + #endif drm_ioctl_t drm_version;
The global bridges_list holding all the bridges between drm_bridge_add() and drm_bridge_remove() cannot be inspected via debugfs. Add a file showing it. To avoid code duplication, move the code printing a bridge info to a common function. Note: this change requires exporting bridge_list and the mutex protecting it. Also add a comment about bridge_lock to make checkpatch happy. Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com> --- This patch was added in v6. --- drivers/gpu/drm/drm_bridge.c | 5 +-- drivers/gpu/drm/drm_debugfs.c | 70 +++++++++++++++++++++++++++++------------- drivers/gpu/drm/drm_drv.c | 1 + drivers/gpu/drm/drm_internal.h | 9 ++++++ 4 files changed, 61 insertions(+), 24 deletions(-)