Wei Chen [off-list ref] wrote:

If there is a failure during copy_from_user or user-provided data buffer
is invalid, rtl_debugfs_set_write_rfreg should return negative error code
instead of a positive value count.

Fix this bug by returning correct error code. Moreover, the check of buffer
against null is removed since it will be handled by copy_from_user.

Fixes: 610247f46feb ("rtlwifi: Improve debugging by using debugfs")
Signed-off-by: Wei Chen <redacted>
Reviewed-by: Simon Horman <redacted>

Patch applied to wireless-next.git, thanks.

905a9241e4e8 wifi: rtlwifi: fix incorrect error codes in rtl_debugfs_set_write_rfreg()

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20230326053138.91338-1-harperchen1110@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches