RE: [PATCH] mmc: dw_mmc: fix status error for Kingston brand SD cards

[Dinh Nguyen <dinguyen@altera.com>]

On Fri, 2014-03-28 at 21:32 +0900, Seungwon Jeon wrote:
> Hi Dinh,
> 
> On Fri, March 28, 2014, Dinh Nguyen wrote:
> > From: Dinh Nguyen <dinguyen@altera.com>
> > 
> > commits [90c2143a8f mmc: dw_mmc: guarantee stop-abort cmd in data errors]
> > and [e352c813110 mmc: dw_mmc: rework the code related to cmd/data completion]
> > cause the SD/MMC DMA interface to stop working on Kingston brand SD cards.
> > 
> > ---
> > Hi Seungwon,
> > 
> > I am seeing this error on v3.13 kernel of the dw_mmc driver:
> > 
> > mmc0: problem reading SD Status register.
> > mmc0: error -110 whilst initialising SD card
> > 
> > I only see this error on a Kingston brand card, although I have heard reports
> > that it also fails a Samsung card. Also it only fails when with
> > CONFIG_MMC_DW_IDMAC=y.
> > 
> > The patch below seems to fix it for me. Any chance you have seen this error?
> I didn't see but I'll try to find it.
> And do you have any analysis for this issue?

Thanks. Here's the debug output that I am seeing. 

With patch applied:

[    2.503394] mmc0: req done (CMD51): 0: 00000920 00000000 00000000
00000000
[    2.510239] mmc0:     8 bytes transferred: 0
[    2.514519] mmc0: starting CMD55 arg 00070000 flags 00000095
[    2.520452] mmc0: req done (CMD55): 0: 00000920 00000000 00000000
00000000
[    2.527324] mmc0: starting CMD13 arg 00000000 flags 000001b5
[    2.532974] mmc0:     blksz 64 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[    2.541526] dwmmc_socfpga ff704000.dwmmc0: data error, status
0x00000800
[    2.548203] mmc0: req done (CMD13): 0: 00000920 00000000 00000000
00000000
[    2.555057] mmc0:     0 bytes transferred: -5
[    2.559410] mmc0: problem reading SD Status register.
[    2.564459] mmc0: starting CMD6 arg 00fffff0 flags 000000b5
[    2.570008] mmc0:     blksz 64 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[    2.578703] mmc0: req done (CMD6): 0: 00000900 00000000 00000000
00000000
[    2.585471] mmc0:     64 bytes transferred: 0
[    2.589829] mmc_host mmc0: card is read-write
[    2.594182] mmc0: starting CMD6 arg 80fffff1 flags 000000b5
[    2.599733] mmc0:     blksz 64 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[    2.609308] mmc0: req done (CMD6): 0: 00000900 00000000 00000000
00000000
[    2.616076] mmc0:     64 bytes transferred: 0
[    2.620434] mmc0: clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 21
width 0 timing 2
[    2.628076] mmc0: clock 50000000Hz busmode 2 powermode 2 cs 0 Vdd 21
width 0 timing 2


Without patch:

[    2.503381] mmc0: req done (CMD51): 0: 00000920 00000000 00000000
00000000
[    2.510226] mmc0:     8 bytes transferred: 0
[    2.514505] mmc0: starting CMD55 arg 00070000 flags 00000095
[    2.520437] mmc0: req done (CMD55): 0: 00000920 00000000 00000000
00000000
[    2.527309] mmc0: starting CMD13 arg 00000000 flags 000001b5
[    2.532960] mmc0:     blksz 64 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[    2.541509] dwmmc_socfpga ff704000.dwmmc0: data error, status
0x00000080
[    2.548185] mmc0: req done (CMD13): 0: 00000920 00000000 00000000
00000000
[    2.555038] mmc0:     0 bytes transferred: -84
[    2.559477] mmc0: problem reading SD Status register.
[    2.564528] mmc0: starting CMD6 arg 00fffff0 flags 000000b5
[    2.570078] mmc0:     blksz 64 blocks 1 flags 00000200 tsac 100 ms
nsac 0
[    2.577814] mmc0: req done (CMD6): -110: 00000920 00000000 00000000
00000000
[    2.584841] mmc0:     0 bytes transferred: -115
[    2.589375] mmc0: error -110 whilst initialising SD card


> 
> > 
> > Dinh
> > ---
> >  drivers/mmc/host/dw_mmc.c |    8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> > index 7833002..7dcaa30 100644
> > --- a/drivers/mmc/host/dw_mmc.c
> > +++ b/drivers/mmc/host/dw_mmc.c
> > @@ -1312,7 +1312,8 @@ static void dw_mci_tasklet_func(unsigned long priv)
> >  			if (test_and_clear_bit(EVENT_DATA_ERROR,
> >  					       &host->pending_events)) {
> >  				dw_mci_stop_dma(host);
> > -				send_stop_abort(host, data);
> > +				if (data->stop)
> > +					send_stop_abort(host, data);
> This routine is for error handing.
> Is it effective to detect card normally?
> 

Yes, detecting the card works fine.

Thanks,
Dinh
> Thanks,
> Seungwon Jeon
> 
> >  				state = STATE_DATA_ERROR;
> >  				break;
> >  			}
> > @@ -1334,6 +1335,11 @@ static void dw_mci_tasklet_func(unsigned long priv)
> >  			set_bit(EVENT_DATA_COMPLETE, &host->completed_events);
> >  			err = dw_mci_data_complete(host, data);
> > 
> > +			if (!data->stop) {
> > +				dw_mci_request_end(host, host->mrq);
> > +				goto unlock;
> > +			}
> > +
> >  			if (!err) {
> >  				if (!data->stop || mrq->sbc) {
> >  					if (mrq->sbc)
> > --
> > 1.7.9.5
> > 
> > --
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