Messages in this thread | | | Subject | Re: [PATCH 2/3] scsi: ufs: Keep device power on only fWriteBoosterBufferFlushDuringHibernate == 1 | From | Bean Huo <> | Date | Thu, 03 Dec 2020 12:45:00 +0100 |
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On Thu, 2020-12-03 at 10:46 +0000, Avri Altman wrote: > > > > From: Bean Huo <beanhuo@micron.com> > > > > > > > > Keep device power mode as active power mode and VCC supply only > > > > if > > > > fWriteBoosterBufferFlushDuringHibernate setting 1 is > > > > successful. > > > > Hi Avri > > Thanks so much taking time reiew. > > > > > Why would it fail? > > > > During the reliability testing in harsh environments, such as: > > EMS testing, in the high/low-temperature environment. The system > > would > > reboot itself, there will be programming failure very likely. > > If we assume failure will never hit, why we capture its result > > following with dev_err(). If you keep using your phone in a harsh > > environment, you will see this print message. > > > > Of course, in a normal environment, the chance of failure likes you > > to > > win a lottery, but the possibility still exists. > > Exactly.
so, you agree the possiblity of failure exists.
> Hence we need-not any extra logic protecting device management > command failures.
what extra logic?
> > if reading the configuration pass correctly, and UFSHCD_CAP_WB_EN is > set,
UFSHCD_CAP_WB_EN set is DRAM level. still in the cache.
> one should expect that any other functionality would work. > No, The programming will consume more power than reading, the later setting will more possbile fail than reading.
> Otherwise, any non-standard behavior should be added with a quirk. >
NO, this is not what is standard or non-standard. This is independent of UFS device/controller. It is a software design. IMO, we didn't deal with programming status that is a potential bug. If having to impose to a component, do you think should be controller or device? Instead of addin a quirk, I prefer dropping this patch.
> Thanks, > Avri > > > > > > > Since UFSHCD_CAP_WB_EN is toggled off on ufshcd_wb_probe If the > > > device doesn't support wb, > > > The check ufshcd_is_wb_allowed should suffice, isn't it? > > > > > > > No, UFSHCD_CAP_WB_EN only tells us if the platform supports WB, > > doesn't tell us fWriteBoosterBufferFlushDuringHibernate status. > > > > Thanks, > > Bean
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