Messages in this thread | | | Date | Thu, 21 Dec 2023 20:13:17 +0100 | Subject | Re: [PATCH RFC v3 00/11] scsi: ufs: Remove overzealous memory barriers | From | Konrad Dybcio <> |
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On 21.12.2023 20:09, Andrew Halaney wrote: > This is an RFC because I'm not all the confident in this topic. 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). If I understand this correctly - and I'm no expert - it's probably good practice to read it back in critical places, so that if the code around it changes, the most crucial writes arrive when expected.
Konrad
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