From: Yuan Can Date: Thu, 3 Nov 2022 01:47:05 +0000 (+0000) Subject: drm/vc4: Fix missing platform_unregister_drivers() call in vc4_drm_register() X-Git-Tag: v6.1-rc5~23^2~2^2~5 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=cf53db768a8790fdaae2fa3a81322b080285f7e5;p=linux-2.6-block.git 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 Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20221103014705.109322-1-yuancan@huawei.com --- 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)