Messages in this thread | | | Subject | Re: [PATCH] scsi: ufshpb: Opt out pre-reqs from HPB2.0 flows | From | Bart Van Assche <> | Date | Fri, 29 Oct 2021 09:10:10 -0700 |
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On 10/29/21 8:57 AM, Avri Altman wrote: > HPB allows its read commands to carry the physical addresses along with > the LBAs, thus allowing less internal L2P-table switches in the device. > HPB1.0 allowed a single LBA, while HPB2.0 increases this capacity up to > 255 blocks. > > Carrying more than a single record, the read operation is no longer > purly of type "read" per-se, but some sort of a "hybrid" command - ^^^^^ purely? > writing the physical address to the device and reading the required > payload. > > The HPB JEDEC spec came-up with a dual-command for that operation: > HPB-WRITE-BUFFER (0x2) to write the physical addresses to device, and > HPB-READ to read the payload. > > Alas, the current HPB driver design - a single-scsi-LLD-module, has no > other alternative but to spawn the READ10 command into 2 commands: > HPB-WRITE-BUFFER and HPB-READ. > This causes a grat deal of aggrevation to the block layer guys, up to a > point, in which that they were willing to revert the entire HPB driver, > regardless of the huge amount of corporate effort already inversted in > it. > > Therefore, remove the pre-req API for now, as a matter of urgency to get > it done before the closing of the merge window.
Anyway:
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
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