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? 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
