Re: [PATCH v2 13/20] scsi: ufs: Fix a deadlock in the error handler

Bart Van Assche
2021-12-01T18:31:53Z

On 12/1/21 5:44 AM, Bean Huo wrote:
> How about adding a hardware-specific UFS device management queue to the
> UFS device? Compared with NVMe and eMMC CMDQ, they both have dedicated
> tags for device management commands. NVMe is queue 0, eMMC CMDQ is CMDQ
> slot 31.
>
> I'm thinking about the benefits of using this device manage queue. If
> the benefits are significant, we can submit the Jedec proposal for the
> UFS equipment management queue.

Hi Bean,

Do you want to modify UFSHCI 4.0 or UFSHCI 3.0? As you may know UFSHCI 4.0
will support multiple queues. The proposal is called multi-circular queue
(MCQ). Since UFSHCI 4.0 has not yet been ratified the draft is only available
to JEDEC members.

For UFSHCI 3.0, how about increasing the number of tags instead of adding an
additional queue? Increasing the number of tags probably will be easier to
implement in existing UFS host controllers than adding a new queue.

Thanks,

Bart.