[U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some MMC cards
Yangbo Lu
yangbo.lu at nxp.com
Tue Aug 2 09:16:40 CEST 2016
Thank you, Jaehoon.
So I will send the new version later :)
Best regards,
Yangbo Lu
> -----Original Message-----
> From: Jaehoon Chung [mailto:jh80.chung at samsung.com]
> Sent: Tuesday, August 02, 2016 3:13 PM
> To: Yangbo Lu; Ziyuan Xu; u-boot at lists.denx.de; Tom Rini
> Cc: Pantelis Antoniou
> Subject: Re: [U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some MMC
> cards
>
> On 08/02/2016 04:03 PM, Yangbo Lu wrote:
> > Hi Jaehoon,
> >
> >
> >> -----Original Message-----
> >> From: Jaehoon Chung [mailto:jh80.chung at samsung.com]
> >> Sent: Thursday, July 28, 2016 4:40 PM
> >> To: Yangbo Lu; Ziyuan Xu; u-boot at lists.denx.de; Tom Rini
> >> Cc: Pantelis Antoniou
> >> Subject: Re: [U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some MMC
> >> cards
> >>
> >> Hi Yangbo,
> >>
> >> On 07/28/2016 11:45 AM, Yangbo Lu wrote:
> >>> Hi Ziyuan and Jaehoon,
> >>>
> >>>
> >>>> -----Original Message-----
> >>>> From: Ziyuan Xu [mailto:xzy.xu at rock-chips.com]
> >>>> Sent: Wednesday, July 27, 2016 9:37 PM
> >>>> To: Jaehoon Chung; Yangbo Lu; u-boot at lists.denx.de; Tom Rini
> >>>> Cc: Pantelis Antoniou
> >>>> Subject: Re: [U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some
> >>>> MMC cards
> >>>>
> >>>>
> >>>>
> >>>> On 2016年07月27日 19:15, Jaehoon Chung wrote:
> >>>>> On 07/27/2016 04:28 PM, Yangbo Lu wrote:
> >>>>>> Hi Tom,
> >>>>>>
> >>>>>> Could you help to assign this mmc patch reviewing to right person?
> >>>>>> It seems no one had reviewed it for almost half year.
> >>>>>>
> >>>>>> And another my mmc patch also needs to be reviewed.
> >>>>>> I submitted in May. Please help.
> >>>>>> http://patchwork.ozlabs.org/patch/624448/
> >>>>>>
> >>>>>>
> >>>>>> Thank you very much.
> >>>>>>
> >>>>>>
> >>>>>> Best regards,
> >>>>>> Yangbo Lu
> >>>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: Yangbo Lu [mailto:yangbo.lu at nxp.com]
> >>>>>>> Sent: Wednesday, March 09, 2016 11:00 AM
> >>>>>>> To: u-boot at lists.denx.de
> >>>>>>> Cc: Pantelis Antoniou; Yangbo Lu
> >>>>>>> Subject: [PATCH] mmc: send CMD0 before CMD1 for some MMC cards
> >>>>>>>
> >>>>>>> When the MMC framework was added in u-boot, the mmc_go_idle was
> >>>>>>> added before mmc_send_op_cond_iter in function mmc_send_op_cond
> >>>>>>> annotating that some cards seemed to need this. Actually, we
> >>>>>>> still need to do this in function mmc_complete_op_cond for those
> cards.
> >>>>>>> This has been verified on Micron MTFC4GACAECN eMMC chip.
> >>>>> If there is no go_idle(), then what happen?
> >>>>> If you share the information more, i can check the more..
> >>>> Sounds interesting, I also want want to know what happen?
> >>>> It seems like you failed in CMD1? The eMMC device was always in
> >>>> busy device within 1 second?
> >>>
> >>> [Lu Yangbo-B47093] This was an issue which our customer reported and
> >> required us to fix in March.
> >>> They used NXP LS1020A platform and Micron MTFC4GACAECN eMMC, and
> >> reported they had to add CMD0 as below.
> >>> Otherwise it couldn’t read OCR.
> >>>
> >>> static int mmc_complete_op_cond(struct mmc *mmc) {
> >>> struct mmc_cmd cmd;
> >>> int timeout = 1000;
> >>> uint start;
> >>> int err;
> >>>
> >>> #if defined (XXX_CHANGED)
> >>> // our eMMC chip (Micron MTFC4GACAECN) requires that it be put in
> >> idle mode before
> >>> // negociating the operating voltage levels.
> >>> mmc_go_idle(mmc);
> >>> #endif
> >>
> >> Well, it seems to fix workaround. mmc_go_idle() means Device Reset.
> >>
> >> mmc_complete_op_cond() function has added for reducing the booting
> time.
> >> If mmc_go_idle() is added at here, there is no benefit, and it should
> >> be back to old concept.
> >>
> >> I don't agree this patch..now.
> >>
> >
> > [Lu Yangbo-B47093] Did you notice mmc_send_op_cond function? Before
> mmc_send_op_cond_iter sending CMD1, there always was mmc_go_idle.
> > I don’t know why said 'Some cards seem to need this', but it must fix
> some issue.
> >
> > static int mmc_send_op_cond(struct mmc *mmc) {
> > int err, i;
> >
> > /* Some cards seem to need this */
> > mmc_go_idle(mmc);
> >
> > /* Asking to the card its capabilities */
> > for (i = 0; i < 2; i++) {
> > err = mmc_send_op_cond_iter(mmc, i != 0);
> > if (err)
> > return err;
> >
> > /* exit if not busy (flag seems to be inverted) */
> > if (mmc->ocr & OCR_BUSY)
> > break;
> > }
> > mmc->op_cond_pending = 1;
> > return 0;
> > }
> >
> > Now in mmc_complete_op_cond function, there may be the same issue.
> Without the mmc_go_idle, mmc_send_op_cond_iter failed to get ocr.
> > Maybe I should move mmc_go_idle just before mmc_send_op_cond_iter, like
> this.
> >
> > static int mmc_complete_op_cond(struct mmc *mmc) {
> > struct mmc_cmd cmd;
> > int timeout = 1000;
> > uint start;
> > int err;
> >
> > mmc->op_cond_pending = 0;
> > if (!(mmc->ocr & OCR_BUSY)) {
> > start = get_timer(0);
> > while (1) {
> > /* Some cards seem to need this */
> > mmc_go_idle(mmc);
> > err = mmc_send_op_cond_iter(mmc, 1);
>
> If you need to add the mmc_go_idle(), then I think this point is right. :)
>
> Best Regards,
> Jaehoon Chung
>
> >
> > If you think it's not proper, do you have any suggestion?
> > :)
> >
> > Thanks a lot.
> >
> >> Best Regards,
> >> Jaehoon Chung
> >>
> >>>
> >>>
> >>> I hadn’t reproduce this to get more details about this issue since I
> >> didn’t have one this kind eMMC card that time.
> >>> Thanks.
> >>>
> >>>>>
> >>>>> Best Regards,
> >>>>> Jaehoon Chung
> >>>>>
> >>>>>>> Signed-off-by: Yangbo Lu <yangbo.lu at nxp.com>
> >>>>>>> ---
> >>>>>>> drivers/mmc/mmc.c | 3 +++
> >>>>>>> 1 file changed, 3 insertions(+)
> >>>>>>>
> >>>>>>> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index
> >>>>>>> ede5d6e..82e3268
> >>>>>>> 100644
> >>>>>>> --- a/drivers/mmc/mmc.c
> >>>>>>> +++ b/drivers/mmc/mmc.c
> >>>>>>> @@ -418,6 +418,9 @@ static int mmc_complete_op_cond(struct mmc
> *mmc)
> >>>>>>> uint start;
> >>>>>>> int err;
> >>>>>>>
> >>>>>>> + /* Some cards seem to need this */
> >>>>>>> + mmc_go_idle(mmc);
> >>>>>>> +
> >>>>>>> mmc->op_cond_pending = 0;
> >>>>>>> if (!(mmc->ocr & OCR_BUSY)) {
> >>>>>>> start = get_timer(0);
> >>>>>>> --
> >>>>>>> 2.1.0.27.g96db324
> >>>>>> _______________________________________________
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> >>>>>>
> >>>>>>
> >>>>>>
> >>>>> _______________________________________________
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> >>>
> >
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