On Wed, 3 Mar 2021 at 07:30, DooHyun Hwang <dh0421.hwang@xxxxxxxxxxx> wrote: > > On Tue, 2 Mar 2021 at 10:38, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > >On Wed, 10 Feb 2021 at 06:12, DooHyun Hwang <dh0421.hwang@xxxxxxxxxxx> > >wrote: > >> > >> A power cycle is required if CMD11 fails. > >> CMD11 failure should be handled as no response. > >> > >> If there is a timeout error that means no response to the CMD11, do > >> not send the CMD11 again and the power cycle is required. > >> Any other errors for CMD11 are the same because CMD11 failed. > >> > >> On some bad SD Card, CMD11 may fail but the card may have already > >> invoked the voltage switch sequence. > >> In this case, it is necessary to retry without voltage switching after > >> power cycle. > >> > >> Signed-off-by: DooHyun Hwang <dh0421.hwang@xxxxxxxxxxx> > > > >Applied for next, thanks! > > > >I took the liberty of updating the commit message a bit, to try to clarify > >things. Moreover, I have tagged this for stable kernels. > > > >BTW, did you try to force the error to -EAGAIN, to keep retrying for a > >couple of times? If so, did it end up with the same kind of errors? > > Thank you for reviewing this. > > Yes. I tested with 2 SD cards. > I think the power cycle is needed before retrying > because SD card doesn't respond SD_ROCR_S18A when retrying without power cycle. Thanks for sharing the logs and the details below! If I understand correctly, forcing the error to -EAGAIN combined with the power cycle when the CMD11 fails, actually makes us succeed with the voltage switch in the second retry. Correct? In that case, it seems like a good idea to extend $subject patch to return -EAGAIN in case we get an error from the CMD11, right? [...] > > #4. SD card responded with SD_ROCR_S18A from ACMD41 after power cycle, and change CMD11's error value to -EAGAIN > // send ACMD41 + with SD_OCR_S18R (bit[24]) > <7>[ 156.884623] [0: kworker/0:1: 7] mmc0: starting CMD41 arg 51040000 flags 000000e1 > // resp ACMD41 + with SD_ROCR_S18A (bit[24]) > <7>[ 156.884975] I[0: highpool[3]: 5440] mmc0: req done (CMD41): 0: c1ff8000 00000000 00000000 00000000 > // send CMD11 and error occurs > <7>[ 156.885051] [0: kworker/0:1: 7] mmc0: starting CMD11 arg 00000000 flags 00000015 > <7>[ 156.885759] I[0: highpool[3]: 5440] mmc0: req done (CMD11): -84: 00000000 00000000 00000000 00000000 > // retry with power cycle (tested with this patch) > <7>[ 156.885834] [0: kworker/0:1: 7] mmc0: Signal voltage switch failed, power cycling card > <7>[ 156.885875] [0: kworker/0:1: 7] mmc0: clock 0Hz busmode 2 powermode 0 cs 0 Vdd 0 width 1 timing 0 > <7>[ 156.920185] [0: kworker/0:1: 7] mmc0: clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 18 width 1 timing 0 > // change CMD11's error value to -EAGAIN > <3>[ 156.932288] [0: kworker/0:1: 7] mmc_sd_get_cid: rocr=0xc1ff8000, retries=10. err=-84 -> -11. > <7>[ 156.932336] [0: kworker/0:1: 7] mmc0: clock 400000Hz busmode 2 powermode 2 cs 1 Vdd 18 width 1 timing 0 > <7>[ 156.933834] [0: kworker/0:1: 7] mmc0: starting CMD0 arg 00000000 flags 000000c0 > <7>[ 156.934101] I[0:ung.android.mdx:10229] mmc0: req done (CMD0): 0: 00000000 00000000 00000000 00000000 > <7>[ 156.935562] [0: kworker/0:1: 7] mmc0: clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 18 width 1 timing 0 > <7>[ 156.937009] [0: kworker/0:1: 7] mmc0: starting CMD8 arg 000001aa flags 000002f5 > <7>[ 156.937372] I[0:ung.android.mdx:10229] mmc0: req done (CMD8): 0: 000001aa 00000000 00000000 00000000 > // send ACMD41 + with SD_OCR_S18R (bit[24]) > <7>[ 157.044190] [0: kworker/0:1: 7] mmc0: starting CMD55 arg 00000000 flags 000000f5 > <7>[ 157.044924] I[0:ung.android.mdx:10229] mmc0: req done (CMD55): 0: 00000120 00000000 00000000 00000000 > <7>[ 157.045023] [0: kworker/0:1: 7] mmc0: starting CMD41 arg 51040000 flags 000000e1 > // resp ACMD41 + with SD_ROCR_S18A (bit[24]) > <7>[ 157.045389] I[0:ung.android.mdx:10229] mmc0: req done (CMD41): 0: c1ff8000 00000000 00000000 00000000 > // send CMD11 and complete > <7>[ 157.045467] [0: kworker/0:1: 7] mmc0: starting CMD11 arg 00000000 flags 00000015 > <7>[ 157.045855] I[0: Binder:798_2: 805] mmc0: req done (CMD11): 0: 00000320 00000000 00000000 00000000 > > > > > >> --- > >> drivers/mmc/core/core.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index > >> 1136b859ddd8..a6674df2a7bb 100644 > >> --- a/drivers/mmc/core/core.c > >> +++ b/drivers/mmc/core/core.c > >> @@ -1207,7 +1207,7 @@ int mmc_set_uhs_voltage(struct mmc_host *host, > >> u32 ocr) > >> > >> err = mmc_wait_for_cmd(host, &cmd, 0); > >> if (err) > >> - return err; > >> + goto power_cycle; > >> > >> if (!mmc_host_is_spi(host) && (cmd.resp[0] & R1_ERROR)) > >> return -EIO; > >> -- > >> 2.29.0 > >> Kind regards Uffe
