Messages in this thread |  | | Date | Sun, 11 Dec 2022 16:18:59 -0800 | Subject | Re: [PATCH v5 4/4] ufs: core: Remove ufshcd_map_desc_id_to_length function | From | Bart Van Assche <> |
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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@acm.org>
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.
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