On Tue, Mar 21, 2023 at 07:46:51AM -0700, Bart Van Assche wrote: > On 3/20/23 22:58, Christoph Hellwig wrote: >> On Mon, Mar 20, 2023 at 04:49:05PM -0700, Bart Van Assche wrote: >>> When requeuing a request to a zoned block device, preserve the LBA order >>> per zone. >> >> What causes this requeue? > > Hi Christoph, > > Two examples of why the SCSI core can decide to requeue a command are a > retryable unit attention or ufshcd_queuecommand() returning > SCSI_MLQUEUE_HOST_BUSY. For example, ufshcd_queuecommand() returns > SCSI_MLQUEUE_HOST_BUSY while clock scaling is in progress (changing the > frequency of the link between host controller and UFS device). None of these should happen as the upper layers enforce a per-zone queue depth of 1.
