Re: LKFT: arm x15: mmc1: cache flush error -110

[Sowjanya Komatineni]

On 3/10/20 10:27 AM, Sowjanya Komatineni wrote:
> On 3/10/20 10:09 AM, Ulf Hansson wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > [...]
> >
> > > > > > I would like to get the regression fixed asap, but I also would like
> > > > > > to avoid reverting patches, unless really necessary. May I 
> > > > > > propose the
> > > > > > following two options.
> > > > > >
> > > > > > 1. Find out why polling with ->card_busy() or CMD13, for a CMD6 with
> > > > > > an R1 response doesn't work - and then fix that behaviour.
> > > > > >
> > > > > > 2. Set the mmc->max_busy_timeout to zero for sdhci-tegra, which 
> > > > > > makes
> > > > > > the core to always use R1B for CMD6 (and erase). This also means 
> > > > > > that
> > > > > > when the cmd->busy_timeout becomes longer than 11s, sdhci-tegra must
> > > > > > disable the HW busy timeout and just wait "forever".
> > > > > >
> > > > > > If you decide for 2, you can add the software timeout support on 
> > > > > > top,
> > > > > > but make that can be considered as a next step of an improvement,
> > > > > > rather than needed as fix. Note that, I believe there are some 
> > > > > > support
> > > > > > for software timeout already in the sdhci core, maybe you need to
> > > > > > tweak it a bit for your case, I don't know.
> > > > > >
> > > > > > Kind regards
> > > > > > Uffe
> > > > > Hi Uffe
> > > > >
> > > > > Will go with 2nd option and will send patches out when ready.
> > > > Okay, good.
> > > >
> > > > > BTW, Tegra host also supports SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK for
> > > > > data timeout based on host clock when using finite mode (HW busy
> > > > > detection based on DATA TIMEOUT count value when cmd operation 
> > > > > timeout
> > > > > is < 11s for tegra host).
> > > > >
> > > > > So, looks like we cant set host max_busy_timeout to 0 for Tegra 
> > > > > host to
> > > > > force R1B during SWITCH and SLEEP_AWAKE.
> > > > >
> > > > > So, was thinking to introduce host capability 
> > > > > MMC_CAP2_LONG_WAIT_HW_BUSY
> > > > > which can be used for hosts supporting long or infinite HW busy wait
> > > > > detection and will update mmc and mmc_ops drivers to not allow 
> > > > > convert
> > > > > R1B to R1B for hosts with this capability during SLEEP_AWAKE and 
> > > > > SWITCH.
> > > > That seems reasonable, it becomes probably both easier and clearer by
> > > > adding a new host cap.
> > > >
> > > > In any case, let me help out and cook a patch for this for the core
> > > > part (I leave the sdhci change to you). It may be a bit tricky,
> > > > especially since I have currently queued a bunch of new changes for
> > > > v5.7, that enables more users of mmc_poll_for_busy() in the core.
> > > > Maybe I need to temporarily drop them, so we can fix these problems
> > > > first. I will check.
> > > >
> > > > Probably, I would also name the cap MMC_CAP_HW_NEED_RSP_BUSY, as that
> > > > seems to be describing the common problem we have for sdhci
> > > > omap/tegra.
> > > >
> > > > Finally, it seems like MMC_CAP_WAIT_WHILE_BUSY should be set for
> > > > sdhci- tegra, so while at it, perhaps you can cook a patch for that as
> > > > well.
> > > >
> > > > Kind regards
> > > > Uffe
> > > OK, I sent v1 yesterday. Please ignore them then.
> > Oh, I haven't seen them. In any case, I am ignoring them.
> >
> > > Will send out patches only for HW busy wait modes program based on cmd
> > > timeout and WAIT_WHILE_BUSY enabled.
> > Great, thanks!
> >
> > Please help test the series I just posted as well, if you have the
> > time ofcourse.
> >
> > Kind regards
> > Uffe
>
> Sure,
>
> Thanks
>
> Sowjanya


mmc_sleep() also needs update to force R1B when host sets capability 
MMC_CAP_NEED_RSP_BUSY