On 12/11/22 05:05, Arthur Simchaev wrote:
There shouldn't be any restriction of the descriptor size (not the descriptor id for that matter) up to QUERY_DESC_MAX_SIZE. According to the spec, the caller can use any descriptor size, and it is up to the device to return the actual size. Therefore there shouldn't be any sizes hardcoded in the kernel, nor any need to cache it, hence ufshcd_map_desc_id_to_length function is redundant. Always read the descriptors with QUERY_DESC_MAX_SIZE size. Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
I have not yet replied with "Reviewed-by" to this patch so you are not yet allowed to add my Reviewed-by tag to this patch.
+ /* Update descriptor length */ + buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
Should a check be added here that desc_buf[QUERY_DESC_LENGTH_OFFSET] <= QUERY_DESC_MAX_SIZE to protect against firmware bugs? Since QUERY_DESC_MAX_SIZE == 255, adding BUILD_BUG_ON(QUERY_DESC_SIZE != 255) and a comment may be sufficient. Thanks, Bart.
