commit 47078311b8 upstream.
A problem about modprobe ingenic-drm failed is triggered with the following
log given:
[ 303.561088] Error: Driver 'ingenic-ipu' is already registered, aborting...
modprobe: ERROR: could not insert 'ingenic_drm': Device or resource busy
The reason is that ingenic_drm_init() returns platform_driver_register()
directly without checking its return value, if platform_driver_register()
failed, it returns without unregistering ingenic_ipu_driver_ptr, resulting
the ingenic-drm can never be installed later.
A simple call graph is shown as below:
ingenic_drm_init()
platform_driver_register() # ingenic_ipu_driver_ptr are registered
platform_driver_register()
driver_register()
bus_add_driver()
priv = kzalloc(...) # OOM happened
# return without unregister ingenic_ipu_driver_ptr
Fixing this problem by checking the return value of
platform_driver_register() and do platform_unregister_drivers() if
error happened.
Fixes: fc1acf317b ("drm/ingenic: Add support for the IPU")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20221104064512.8569-1-yuancan@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
d829cafff5