On 3/24/23 19:00, Damien Le Moal wrote:
The trick here could be to have the UFS LLD to unlock the target zone of a write
when the command is sent to the device, instead of when the command completes.
This way, the zone is still locked when there is a requeue and there is no
reordering. That could allow for write qd > 1 in the case of UFS. And this
method could actually work for regular writes too.
Hi Damien,
Although the above sounds interesting to me, I think the following two
scenarios are not handled by the above approach and can lead to reordering:
* The SCSI device reporting a unit attention.
* The SCSI device responding with the SCSI status "BUSY". The UFS
standard explicitly allows this. From the UFS standard: "If the unit is
not ready to accept a new command (e.g., still processing previous
command) a STATUS response of BUSY will be returned."
Thanks,
Bart.
