kernel/linux.git/drivers/base/component.c, branch v6.6.132

drivers: base: component: fix memory leak with using debugfs_lookup()

2023-02-08T12:33:10+00:00

When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Cc: "Rafael J. Wysocki" Link: https://lore.kernel.org/r/20230202141621.2296458-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

component: Add common helper for compare/release functions

2022-02-25T11:16:12+00:00

The component requires the compare/release functions, there are so many copies in current kernel. Just define four common helpers for them. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Signed-off-by: Yong Wu Link: https://lore.kernel.org/r/20220214060819.7334-2-yong.wu@mediatek.com Signed-off-by: Greg Kroah-Hartman

component: Replace most references to 'master' with 'aggregate device'

2022-01-31T13:45:35+00:00

Remove most references to 'master' in the code and replace them with some form of 'aggregate device'. This better reflects the reality of what this code does, i.e. an aggregate device that represents a device like a GPU card once some set of devices that make up the aggregate device probe and register with the component framework. Cc: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Laurent Pinchart Cc: "Rafael J. Wysocki" Cc: Rob Clark Cc: Russell King Cc: Saravana Kannan Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20220127200141.1295328-2-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

component: do not leave master devres group open after bind

2021-10-21T11:01:56+00:00

In current code, the devres group for aggregate master is left open after call to component_master_add_*(). This leads to problems when the master does further managed allocations on its own. When any participating driver calls component_del(), this leads to immediate release of resources. This came up when investigating a page fault occurring with i915 DRM driver unbind with 5.15-rc1 kernel. The following sequence occurs: i915_pci_remove() -> intel_display_driver_unregister() -> i915_audio_component_cleanup() -> component_del() -> component.c:take_down_master() -> hdac_component_master_unbind() [via master->ops->unbind()] -> devres_release_group(master->parent, NULL) With older kernels this has not caused issues, but with audio driver moving to use managed interfaces for more of its allocations, this no longer works. Devres log shows following to occur: component_master_add_with_match() [ 126.886032] snd_hda_intel 0000:00:1f.3: DEVRES ADD 00000000323ccdc5 devm_component_match_release (24 bytes) [ 126.886045] snd_hda_intel 0000:00:1f.3: DEVRES ADD 00000000865cdb29 grp< (0 bytes) [ 126.886049] snd_hda_intel 0000:00:1f.3: DEVRES ADD 000000001b480725 grp< (0 bytes) audio driver completes its PCI probe() [ 126.892238] snd_hda_intel 0000:00:1f.3: DEVRES ADD 000000001b480725 pcim_iomap_release (48 bytes) component_del() called() at DRM/i915 unbind() [ 137.579422] i915 0000:00:02.0: DEVRES REL 00000000ef44c293 grp< (0 bytes) [ 137.579445] snd_hda_intel 0000:00:1f.3: DEVRES REL 00000000865cdb29 grp< (0 bytes) [ 137.579458] snd_hda_intel 0000:00:1f.3: DEVRES REL 000000001b480725 pcim_iomap_release (48 bytes) So the "devres_release_group(master->parent, NULL)" ends up freeing the pcim_iomap allocation. Upon next runtime resume, the audio driver will cause a page fault as the iomap alloc was released without the driver knowing about it. Fix this issue by using the "struct master" pointer as identifier for the devres group, and by closing the devres group after the master->ops->bind() call is done. This allows devres allocations done by the driver acting as master to be isolated from the binding state of the aggregate driver. This modifies the logic originally introduced in commit 9e1ccb4a7700 ("drivers/base: fix devres handling for master device") Fixes: 9e1ccb4a7700 ("drivers/base: fix devres handling for master device") Cc: stable@vger.kernel.org Acked-by: Imre Deak Acked-by: Russell King (Oracle) Signed-off-by: Kai Vehmanen BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/4136 Link: https://lore.kernel.org/r/20211013161345.3755341-1-kai.vehmanen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

drivers/base/component.c: remove superfluous header files from component.c

2021-10-05T14:21:10+00:00

component.c hasn't use any macro or function declared in linux/kref.h. Thus, these files can be removed from component.c safely without affecting the compilation of the drivers/base/ module Signed-off-by: Mianhan Liu Link: https://lore.kernel.org/r/20210928193849.28717-1-liumh1@shanghaitech.edu.cn Signed-off-by: Greg Kroah-Hartman

component: Rename 'dev' to 'parent'

2021-05-27T13:49:59+00:00

Let's rename this struct member to 'parent' to better reflect the reality that it's the parent device of this psuedo-device. In the next patch we'll put a 'struct device' inside of this struct so moving this away simplifies that patch by reducing the number of places that 'dev' is modified. Cc: Daniel Vetter Cc: "Rafael J. Wysocki" Cc: Rob Clark Cc: Russell King Cc: Saravana Kannan Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20210520002519.3538432-3-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

component: Drop 'dev' argument to component_match_realloc()

2021-05-27T13:49:32+00:00

This argument isn't used. Drop it. Cc: Daniel Vetter Cc: "Rafael J. Wysocki" Cc: Rob Clark Cc: Russell King Cc: Saravana Kannan Signed-off-by: Stephen Boyd Link: https://lore.kernel.org/r/20210520002519.3538432-2-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman

driver core: component: remove dentry pointer in "struct master"

2021-03-23T09:49:02+00:00

There is no need to keep around a pointer to a dentry when all it is used for is to remove the debugfs file when tearing things down. As the name is simple, have debugfs look up the dentry when removing things, keeping the logic much simpler. Cc: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20210216142400.3759099-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

component: Silence bind error on -EPROBE_DEFER

2020-04-28T15:54:15+00:00

If a component fails to bind due to -EPROBE_DEFER we should not log an error as this is not a real failure. Fixes messages like: vc4-drm soc:gpu: failed to bind 3f902000.hdmi (ops vc4_hdmi_ops): -517 vc4-drm soc:gpu: master bind failed: -517 Signed-off-by: James Hilliard Link: https://lore.kernel.org/r/20200411190241.89404-1-james.hilliard1@gmail.com Signed-off-by: Greg Kroah-Hartman

component: allow missing unbind callback

2020-03-18T13:13:33+00:00

The component framework reuses the devres managed functions. There is no need to specify an unbind() callback if the driver only wants to release the devres managed resources. The bind/unbind is like the probe/remove pair. The bind/probe is necessary and the unbind/remove is optional. Signed-off-by: Marco Felsch Reviewed-by: Philipp Zabel Link: https://lore.kernel.org/r/20200227104547.30085-1-m.felsch@pengutronix.de Signed-off-by: Greg Kroah-Hartman