On Fri, 29 Mar 2024 15:46:42 -0500, Andrew Halaney wrote:
> Please review with care as I'm not all that confident in this subject.
> UFS has a lot of mb() variants used, most with comments saying "ensure this
> takes effect before continuing". mb()'s aren't really the way to
> guarantee that, a read back is the best method.
>
> Some of these though I think could go a step further and remove the mb()
> variant without a read back. As far as I can tell there's no real reason
> to ensure it takes effect in most cases (there's no delay() or anything
> afterwards, and eventually another readl()/writel() happens which is by
> definition ordered). Some of the patches in this series do that if I was
> confident it was safe (or a reviewer pointed out prior that they thought
> it was safe to do so).
>
> [...]
Applied to 6.10/scsi-queue, thanks!
[01/11] scsi: ufs: qcom: Perform read back after writing reset bit
https://git.kernel.org/mkp/scsi/c/c4d28e06b0c9
[02/11] scsi: ufs: qcom: Perform read back after writing REG_UFS_SYS1CLK_1US
https://git.kernel.org/mkp/scsi/c/a862fafa263a
[03/11] scsi: ufs: qcom: Remove unnecessary mb() after writing testbus config
https://git.kernel.org/mkp/scsi/c/95d26dda90df
[04/11] scsi: ufs: qcom: Perform read back after writing unipro mode
https://git.kernel.org/mkp/scsi/c/823150ecf04f
[05/11] scsi: ufs: qcom: Perform read back after writing CGC enable
https://git.kernel.org/mkp/scsi/c/d9488511b3ac
[06/11] scsi: ufs: cdns-pltfrm: Perform read back after writing HCLKDIV
https://git.kernel.org/mkp/scsi/c/b715c55daf59
[07/11] scsi: ufs: core: Perform read back after writing UTP_TASK_REQ_LIST_BASE_H
https://git.kernel.org/mkp/scsi/c/408e28086f1c
[08/11] scsi: ufs: core: Perform read back after disabling interrupts
https://git.kernel.org/mkp/scsi/c/e4a628877119
[09/11] scsi: ufs: core: Perform read back after disabling UIC_COMMAND_COMPL
https://git.kernel.org/mkp/scsi/c/4bf3855497b6
[10/11] scsi: ufs: core: Remove unnecessary wmb() after ringing doorbell
https://git.kernel.org/mkp/scsi/c/d3fb9a24a602
[11/11] scsi: ufs: core: Remove unnecessary wmb() prior to writing run/stop regs
https://git.kernel.org/mkp/scsi/c/356a8ce7cd50
--
Martin K. Petersen Oracle Linux Engineering
