Messages in this thread | | | Subject | Re: [PATCH V2 0/5] mmc: mmci: add busy detect for stm32 sdmmc variant | From | Ludovic BARRE <> | Date | Fri, 3 May 2019 17:15:03 +0200 |
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hi Ulf
On 5/3/19 3:29 PM, Ulf Hansson wrote: > On Tue, 30 Apr 2019 at 14:06, Ludovic BARRE <ludovic.barre@st.com> wrote: >> >> >> >> On 4/30/19 1:13 PM, Ulf Hansson wrote: >>> On Fri, 26 Apr 2019 at 09:46, Ludovic Barre <ludovic.Barre@st.com> wrote: >>>> >>>> From: Ludovic Barre <ludovic.barre@st.com> >>>> >>>> This patch series adds busy detect for stm32 sdmmc variant. >>>> Some adaptations are required: >>>> -Avoid to check and poll busy status when is not expected. >>>> -Clear busy status bit if busy_detect_flag and busy_detect_mask are >>>> different. >>>> -Add hardware busy timeout with MMCIDATATIMER register. >>>> >>>> V2: >>>> -mmci_cmd_irq cleanup in separate patch. >>>> -simplify the busy_detect_flag exclude >>>> -replace sdmmc specific comment in >>>> "mmc: mmci: avoid fake busy polling in mmci_irq" >>>> to focus on common behavior >>>> >>>> Ludovic Barre (5): >>>> mmc: mmci: cleanup mmci_cmd_irq for busy detect feature >>>> mmc: mmci: avoid fake busy polling in mmci_irq >>>> mmc: mmci: fix clear of busy detect status >>>> mmc: mmci: add hardware busy timeout feature >>>> mmc: mmci: add busy detect for stm32 sdmmc variant >>>> >>>> drivers/mmc/host/mmci.c | 61 ++++++++++++++++++++++++++++++++++++++----------- >>>> drivers/mmc/host/mmci.h | 3 +++ >>>> 2 files changed, 51 insertions(+), 13 deletions(-) >>>> >>>> -- >>>> 2.7.4 >>>> >>> >>> Ludovic, just wanted to let you know that I am reviewing and testing >>> this series. >>> >>> However, while running some tests on Ux500 for validating the busy >>> detection code, even without your series applied, I encounter some odd >>> behaviors. I am looking into the problem to understand better and will >>> let you know as soon as I have some more data to share. >> >> Oops, don't hesitate to share your status, if I could help. > > Thanks! Good and bad news here, then. > > I now understand what is going on - and there is certainly room for > improvements here, but more importantly the actual mmci busy detection > works as expected. > > When it comes to improvements, the main issue I have found is how we > treat DATA WRITES. In many cases we simply don't use the HW busy > detection at all, but instead rely on the mmc core to send CMD13 in a > loop to poll. Well, then if the polling would have consisted of a > couple of CMD13s that wouldn't be an issue, but my observations is > rather that the numbers of CMD13 sent to poll is in the range or > hundreds/thousands - per each WRITE request! > > I am going to send a patch (or two) that improves the behavior. It > might even involve changing parts in core layer, not sure how the end > result will look like yet.
yes, these will improve the drivers without hardware busy completion. great
> > In any case, I have applied patch 1 and patch2 for next, as the tests > turned out well at my side. I also took the liberty of updating some > of the comments/changelogs, please have look and tell if there is > something you want to change. > > I will continue with the rest of series next week.
thanks, and good week-end.
> > Kind regards > Uffe >
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