On 09/25/2015 06:41 PM, Hans de Goede wrote: > Hi, > > On 25-09-15 11:37, Jaehoon Chung wrote: >> Hi, Hans. >> >> On 09/25/2015 04:53 PM, Hans de Goede wrote: >>> Hi, >>> >>> On 24-09-15 18:04, Doug Anderson wrote: >>>> Hi, >>>> >>>> On Thu, Sep 24, 2015 at 2:19 AM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>>>> Hi, >>>>> >>>>> On 23-09-15 23:43, Ulf Hansson wrote: >>>>>> >>>>>> On 22 September 2015 at 17:30, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>>>>>> >>>>>>> Hi Ulf, >>>>>>> >>>>>>> Here is a non RFC version of my patch-set to wait for card_busy before >>>>>>> starting sdio requests. It is the same as the RFC version of the set, >>>>>>> but this time it has been tested no hardware which actually needs this >>>>>>> and I can confirm now that this fixes wifi on that hardware. >>>>>> >>>>>> >>>>>> Great! Thanks, applied for next! >>>>> >>>>> >>>>> Great, thanks, I guess it is too late for this to go as a fix into >>>>> 4.3-rcX (no worries if it is) ? >>>>> >>>>>>> This patch-set should also allow removing this dw_mmc specific fix: >>>>>>> >>>>>>> >>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/mmc/host/dw_mmc.c?id=0bdbd0e88cf6b603a2196418672715b0890fb040 >>>>>>> >>>>>>> As this patch-set fixes this problem in a generic manner. >>>>>> >>>>>> >>>>>> Care to send a patch to remove the above hack/fix? >>>>> >>>>> >>>>> I do not have any hardware to test this. >>>>> >>>>> I've added Doug the original author of that patch to the Cc. >>>>> >>>>> Dough, can you test if with the patch set from this mail thread >>>>> (merged into mmc/next) this patch: >>>>> >>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/mmc/host/dw_mmc.c?id=0bdbd0e88cf6b603a2196418672715b0890fb040 >>>>> >>>>> Is still necessary ? Since this patch-set fixes the same issue >>>>> in the mmc core I believe that this commit can be reverted now. >>>> >>>> I'll try to find some time in the next few days to test, but I'm not >>>> terribly hopeful we can just revert the patch because: >>>> >>>> 1. Only one of the two callers of dw_mci_wait_while_busy() is handled >>>> by your patch. mci_send_cmd() is used internally in dw_mmc to throw >>>> something in the CMD register without going through the normal MMC >>>> path. This is used exclusively to update the clock registers in >>>> dw_mmc. I'm pretty sure this needs the wait, too. It's always seemed >>>> weird / awkward to me that you need to use the CMD register to update >>>> clock settings in dw_mmc, but c'est la vie. >>> >>> I would not expect the card to signal busy when trying to change clocks >>> though, so I do not think this will really be a problem. >> >> No. It shouldn't be occurred any problem. >> But according to designware TRM, it needs to check whether card is busy or not, before updating clock. >> I think even if problem will not occur, it doesn't mean this code is useless. >> >>> >>>> 2. If I remember correctly, we ran into other instances where non-SDIO >>>> cards needed the busy check. It wasn't terribly common, but I think I >>>> ran into this when stress testing, but only on a few cards. >>> >>> Hmm, that would be a problem yes. >>> >>>> The patch referenced here only seems to check for SDIO commands. As I >>>> understand it, to be correct, it should check for all data commands >>>> (other than stop or voltage change commands). >>> >>> But that is not what the patch does, it actually waits for all commands, >>> including non data commands. An earlier attempt of mine to fix the sdio >>> wifi issues with the sunxi driver copied your approach, and I actually >>> got reports of regressions with using normal micro-sd memory cards >>> from several people testing that patch. >> >> I can't see any problem reported at mailing list. >> Could you share more information what regressions issue? > > IIRC people where hitting the timeout in the code to wait for the card-busy. > > Now that I think about this, this may have been caused by waiting > for card-busy while sending a stop. I understood what problem you said. Well, but i don't accept your opinion yet. Is that case reproduced with dwmmc controller? otherwise...sunxi driver? (It seems that you mentioned the case of sunxi driver.) Best Regards, Jaehoon Chung > > Regards, > > Hans > > > >> >> Best Regards, >> Jaehoon Chung >> >>> >>> And if you're right that we should wait for all data commands, then >>> I wonder if this is a designware thing (I believe the allwinner >>> mmc controller is designware derived) or a generic mmc / sdio thing ? >>> >>>> The Designware Databook >>>> makes no reference to only needing the wait for SDIO commands. >>> >>> Yet your commit message references problems with sdio wifi cards, and >>> on sunxi we've only been seeing this problem with sdio wifi cards / sdio >>> commands. >>> >>>> ...of course, it's always possible that some of the things I saw above >>>> will no longer happen with all the other fixes we've done in the >>>> meantime (turning on voltages at the right time, adding the right >>>> delays, etc). >>>> >>>> >>>> Note that I've hardly looked at sdhci at all, but on SDHCI is this >>>> handled by the "SDHCI_DATA_INHIBIT" bits? >>> >>> Regards, >>> >>> Hans >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
