From: Yuan Can yuancan@huawei.com
[ Upstream commit 4ecff954c370b82bce45bdca2846c5c5563e8a8a ]
A problem about insmod megachips-stdpxxxx-ge-b850v3-fw.ko failed is triggered with the following log given:
[ 4497.981497] Error: Driver 'stdp4028-ge-b850v3-fw' is already registered, aborting... insmod: ERROR: could not insert module megachips-stdpxxxx-ge-b850v3-fw.ko: Device or resource busy
The reason is that stdpxxxx_ge_b850v3_init() returns i2c_add_driver() directly without checking its return value, if i2c_add_driver() failed, it returns without calling i2c_del_driver() on the previous i2c driver, resulting the megachips-stdpxxxx-ge-b850v3-fw can never be installed later. A simple call graph is shown as below:
stdpxxxx_ge_b850v3_init() i2c_add_driver(&stdp4028_ge_b850v3_fw_driver) i2c_add_driver(&stdp2690_ge_b850v3_fw_driver) i2c_register_driver() driver_register() bus_add_driver() priv = kzalloc(...) # OOM happened # return without delete stdp4028_ge_b850v3_fw_driver
Fix by calling i2c_del_driver() on stdp4028_ge_b850v3_fw_driver when i2c_add_driver() returns error.
Fixes: fcfa0ddc18ed ("drm/bridge: Drivers for megachips-stdpxxxx-ge-b850v3-fw (LVDS-DP++)") Signed-off-by: Yuan Can yuancan@huawei.com Reviewed-by: Andrzej Hajda andrzej.hajda@intel.com Tested-by: Ian Ray ian.ray@ge.com Signed-off-by: Robert Foss robert.foss@linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20221108091226.114524-1-yuanca... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c index 97359f807bfc3..cbfa05a6767b5 100644 --- a/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c +++ b/drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c @@ -440,7 +440,11 @@ static int __init stdpxxxx_ge_b850v3_init(void) if (ret) return ret;
- return i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); + ret = i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); + if (ret) + i2c_del_driver(&stdp4028_ge_b850v3_fw_driver); + + return ret; } module_init(stdpxxxx_ge_b850v3_init);