On 08.11.2022 09:29, Yuan Can wrote:
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 <[email protected]> --- drivers/gpu/drm/bridge/megachips-stdpxxxx-ge-b850v3-fw.c | 8 +++++++- 1 file changed, 7 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 97359f807bfc..0d037eeefcf3 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 +440,13 @@ 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; + } + + return 0;
Could be: ret = i2c_add_driver(&stdp2690_ge_b850v3_fw_driver); if (ret) i2c_del_driver(&stdp4028_ge_b850v3_fw_driver); return ret; Up to you. Anyway: Reviewed-by: Andrzej Hajda <[email protected]> Regards Andrzej
} module_init(stdpxxxx_ge_b850v3_init);
