kernel/linux.git/drivers/gpu/drm/drm_debugfs.c, branch v6.6.132

drm: Update file owner during use

2024-01-01T12:42:25+00:00

[ Upstream commit 1c7a387ffef894b1ab3942f0482dac7a6e0a909c ] With the typical model where the display server opens the file descriptor and then hands it over to the client(*), we were showing stale data in debugfs. Fix it by updating the drm_file->pid on ioctl access from a different process. The field is also made RCU protected to allow for lockless readers. Update side is protected with dev->filelist_mutex. Before: $ cat /sys/kernel/debug/dri/0/clients command pid dev master a uid magic Xorg 2344 0 y y 0 0 Xorg 2344 0 n y 0 2 Xorg 2344 0 n y 0 3 Xorg 2344 0 n y 0 4 After: $ cat /sys/kernel/debug/dri/0/clients command tgid dev master a uid magic Xorg 830 0 y y 0 0 xfce4-session 880 0 n y 0 1 xfwm4 943 0 n y 0 2 neverball 1095 0 n y 0 3 *) More detailed and historically accurate description of various handover implementation kindly provided by Emil Velikov: """ The traditional model, the server was the orchestrator managing the primary device node. From the fd, to the master status and authentication. But looking at the fd alone, this has varied across the years. IIRC in the DRI1 days, Xorg (libdrm really) would have a list of open fd(s) and reuse those whenever needed, DRI2 the client was responsible for open() themselves and with DRI3 the fd was passed to the client. Around the inception of DRI3 and systemd-logind, the latter became another possible orchestrator. Whereby Xorg and Wayland compositors could ask it for the fd. For various reasons (hysterical and genuine ones) Xorg has a fallback path going the open(), whereas Wayland compositors are moving to solely relying on logind... some never had fallback even. Over the past few years, more projects have emerged which provide functionality similar (be that on API level, Dbus, or otherwise) to systemd-logind. """ v2: * Fixed typo in commit text and added a fine historical explanation from Emil. Signed-off-by: Tvrtko Ursulin Cc: "Christian König" Cc: Daniel Vetter Acked-by: Christian König Reviewed-by: Emil Velikov Reviewed-by: Rob Clark Tested-by: Rob Clark Link: https://patchwork.freedesktop.org/patch/msgid/20230621094824.2348732-1-tvrtko.ursulin@linux.intel.com Signed-off-by: Christian König Stable-dep-of: 5a6c9a05e55c ("drm: Fix FD ownership check in drm_master_check_perm()") Signed-off-by: Sasha Levin

drm/bridge: Add debugfs print for bridge chains

2023-08-02T08:05:01+00:00

DRM bridges are not visible to the userspace and it may not be immediately clear if the chain is somehow constructed incorrectly. I have had two separate instances of a bridge driver failing to do a drm_bridge_attach() call, resulting in the bridge connector not being part of the chain. In some situations this doesn't seem to cause issues, but it will if DRM_BRIDGE_ATTACH_NO_CONNECTOR flag is used. Add a debugfs file to print the bridge chains. For me, on this TI AM62 based platform, I get the following output: encoder[39] bridge[0] type: 0, ops: 0x0 bridge[1] type: 0, ops: 0x0, OF: /bus@f0000/i2c@20000000/dsi@e:toshiba,tc358778 bridge[2] type: 0, ops: 0x3, OF: /bus@f0000/i2c@20010000/hdmi@48:lontium,lt8912b bridge[3] type: 11, ops: 0x7, OF: /hdmi-connector:hdmi-connector Tested-by: Alexander Stein Reviewed-by: Laurent Pinchart Signed-off-by: Tomi Valkeinen Acked-by: Neil Armstrong Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20230802-drm-bridge-chain-debugfs-v4-1-7e3ae3d137c0@ideasonboard.com

drm: debugfs: Silence warning from cast

2023-07-20T21:43:14+00:00

Casting a pointer to an integer of a different size generates a warning from the compiler. First cast the pointer to a pointer-sized type to keep the compiler happy. Fixes: 4f66feeab173 ("drm: debugfs: provide infrastructure to dump a DRM GPU VA space") Reviewed-by: Danilo Krummrich Signed-off-by: Steven Price Signed-off-by: Danilo Krummrich Link: https://patchwork.freedesktop.org/patch/msgid/010b58cd-1225-02f7-33f0-c678e5cd349d@arm.com

drm: debugfs: provide infrastructure to dump a DRM GPU VA space

2023-07-20T03:16:21+00:00

This commit adds a function to dump a DRM GPU VA space and a macro for drivers to register the struct drm_info_list 'gpuvas' entry. Most likely, most drivers might maintain one DRM GPU VA space per struct drm_file, but there might also be drivers not having a fixed relation between DRM GPU VA spaces and a DRM core infrastructure, hence we need the indirection via the driver iterating it's maintained DRM GPU VA spaces. Reviewed-by: Boris Brezillon Signed-off-by: Danilo Krummrich Link: https://patchwork.freedesktop.org/patch/msgid/20230720001443.2380-3-dakr@redhat.com

drm: Track clients by tgid and not tid

2023-03-15T13:03:00+00:00

Thread group id (aka pid from userspace point of view) is a more interesting thing to show as an owner of a DRM fd, so track and show that instead of the thread id. In the next patch we will make the owner updated post file descriptor handover, which will also be tgid based to avoid ping-pong when multiple threads access the fd. Signed-off-by: Tvrtko Ursulin Reviewed-by: Zack Rusin Reviewed-by: Christian König Signed-off-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20230314141904.1210824-2-tvrtko.ursulin@linux.intel.com

drm/debugfs: use octal permissions instead of symbolic permissions

2023-01-10T12:57:05+00:00

Currently, debugfs functions are using symbolic macros as permission bits, but checkpatch reinforces permission bits in the octal form, as they are more readable and easier to understand [1]. Moreover, using the symbolic macro S_IFREG is redundant. Therefore, use octal permission bits in all debugfs functions. [1] https://docs.kernel.org/dev-tools/checkpatch.html#permissions Suggested-by: Jani Nikula Signed-off-by: Maíra Canal Reviewed-by: Daniel Vetter Reviewed-by: Jani Nikula Signed-off-by: Maíra Canal Link: https://patchwork.freedesktop.org/patch/msgid/20230105193039.287677-1-mcanal@igalia.com

drm/debugfs: create debugfs late register functions

2022-12-22T17:58:55+00:00

Although the device-centered debugfs functions can track requests for the addition of DRM debugfs files at any time and have them added all at once during drm_dev_register(), they are not able to create debugfs files for modeset components, as they are registered after the primary and the render drm_minor are registered. So, create a drm_debugfs_late_register() function, which is responsible for dealing with the creation of all the debugfs files for modeset components at once. Therefore, the functions drm_debugfs_add_file() and drm_debugfs_add_files() can be used in late_register hooks. Signed-off-by: Maíra Canal Reviewed-by: Melissa Wen Acked-by: Daniel Vetter Signed-off-by: Maíra Canal Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-4-mcanal@igalia.com

drm: use new debugfs device-centered functions on DRM core files

2022-12-22T17:58:21+00:00

Replace the use of drm_debugfs_create_files() with the new drm_debugfs_add_files() function in all DRM core files, centering the debugfs files management on the drm_device instead of drm_minor. Signed-off-by: Maíra Canal Reviewed-by: Maxime Ripard Reviewed-by: Melissa Wen Acked-by: Daniel Vetter Signed-off-by: Maíra Canal Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-3-mcanal@igalia.com

drm/debugfs: create device-centered debugfs functions

2022-12-22T17:56:28+00:00

Introduce the ability to track requests for the addition of DRM debugfs files at any time and have them added all at once during drm_dev_register(). Drivers can add DRM debugfs files to a device-managed list and, during drm_dev_register(), all added files will be created at once. Now, the drivers can use the functions drm_debugfs_add_file() and drm_debugfs_add_files() to create DRM debugfs files instead of using the drm_debugfs_create_files() function. Co-developed-by: Wambui Karuga Signed-off-by: Wambui Karuga Signed-off-by: Maíra Canal Reviewed-by: Maxime Ripard Reviewed-by: Melissa Wen Acked-by: Daniel Vetter Signed-off-by: Maíra Canal Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-2-mcanal@igalia.com

drm/edid: abstract debugfs override EDID show better

2022-10-26T06:53:08+00:00

Add a function to dump the override EDID in debugfs. This hides the override EDID management better in drm_edid.c. Signed-off-by: Jani Nikula Reviewed-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/74defa7b595f51e6c1f2eacd9c799d567d29f053.1666614699.git.jani.nikula@intel.com