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| author |   Yuan Can <yuancan@huawei.com> | 2022-11-03 01:47:05 +0000 |
|---|---|---|
| committer |   Maxime Ripard <maxime@cerno.tech> | 2022-11-07 11:29:40 +0100 |
| commit | cf53db768a8790fdaae2fa3a81322b080285f7e5 (patch) | |
| tree | fa78fb1aa5c415dade9d856f58334e5d01f0b798 /drivers/gpu | |
| parent | drm/vc4: hdmi: Fix HSM clock too low on Pi4 (diff) | |
| download | linux-dev-cf53db768a8790fdaae2fa3a81322b080285f7e5.tar.xz linux-dev-cf53db768a8790fdaae2fa3a81322b080285f7e5.zip | |
drm/vc4: Fix missing platform_unregister_drivers() call in vc4_drm_register()
A problem about modprobe vc4 failed is triggered with the following log
given:
[ 420.327987] Error: Driver 'vc4_hvs' is already registered, aborting...
[ 420.333904] failed to register platform driver vc4_hvs_driver [vc4]: -16
modprobe: ERROR: could not insert 'vc4': Device or resource busy
The reason is that vc4_drm_register() returns platform_driver_register()
directly without checking its return value, if platform_driver_register()
fails, it returns without unregistering all the vc4 drivers, resulting the
vc4 can never be installed later.
A simple call graph is shown as below:
vc4_drm_register()
platform_register_drivers() # all vc4 drivers are registered
platform_driver_register()
driver_register()
bus_add_driver()
priv = kzalloc(...) # OOM happened
# return without unregister drivers
Fixing this problem by checking the return value of
platform_driver_register() and do platform_unregister_drivers() if
error happened.
Fixes: c8b75bca92cb ("drm/vc4: Add KMS support for Raspberry Pi.")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103014705.109322-1-yuancan@huawei.com
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_drv.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 2027063fdc30..8c329c071c62 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -476,7 +476,12 @@ static int __init vc4_drm_register(void) if (ret) return ret; - return platform_driver_register(&vc4_platform_driver); + ret = platform_driver_register(&vc4_platform_driver); + if (ret) + platform_unregister_drivers(component_drivers, + ARRAY_SIZE(component_drivers)); + + return ret; } static void __exit vc4_drm_unregister(void) |