Re: [PATCH] mmc: at91_mci: fix hanging and rework to match flowcharts

[Nicolas Ferre]

Pierre Ossman :
> Nicolas Ferre wrote:
> > Fixes hanging using multi block operations (seen during CMD25).
> > Follows closely the datasheet flowcharts.
> >
> > This piece of code handles better big file writing. I had to take care
> > of the notbusy signal during write (at91_mci_handle_cmdrdy function) and
> > to rearrange the AT91_MCI_ENDRX and AT91_MCI_RXBUFF flag usage.
> >
> > Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> > ---
>
> Most of the patch looks ok. Do you want to wait for some more tests or should I
> chuck this into the imminent merge window?

*pong*

I think it is ok to put it into the merge window.

> > @@ -817,7 +834,11 @@ static int __init at91_mci_probe(struct
> >     mmc->ops = &at91_mci_ops;
> >     mmc->f_min = 375000;
> > -    mmc->f_max = 25000000;
> > +    if (cpu_is_at91sam9263())
> > +        mmc->f_max = 50000000;
> > +    else
> > +        mmc->f_max = 25000000;
> > +
> >     mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
> >     mmc->caps = MMC_CAP_BYTEBLOCK | MMC_CAP_MULTIWRITE;
>
> This seems unrelated to the rest of the patch. Also, high-speed won't be enabled
> unless you set the appropriate caps (which should be checked against timing
> specifications, not just assigned and hope for the best).

True. I remove this chunk off the patch.


> > @@ -830,11 +851,11 @@ static int __init at91_mci_probe(struct
> >     host->bus_mode = 0;
> >     host->board = pdev->dev.platform_data;
> >     if (host->board->wire4) {
> > -#ifdef SUPPORT_4WIRE
> > -        mmc->caps |= MMC_CAP_4_BIT_DATA;
> > -#else
> > -        printk("AT91 MMC: 4 wire bus mode not supported by this driver
> > - using 1 wire\n");
> > -#endif
> > +        if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
> > +            mmc->caps |= MMC_CAP_4_BIT_DATA;
> > +        else
> > +            printk("AT91 MMC: 4 wire bus mode not supported"
> > +                " - using 1 wire\n");
> >     }
> >
> >     /*
>
> This also looks unrelated.

Well, It is related to capacities of newer IPs that allow readproof and 
writeproof features that I enable here :

+	if (cpu_is_at91sam9260() || cpu_is_at91sam9263())
+		mr |= AT91_MCI_RDPROOF | AT91_MCI_WRPROOF;

This allows to have a smooth data transmission internally (prevent 
underruns) and so have full 4 wires capacity. So I think this is good 
for having a full featured driver on all chips.

I resend a corrected patch now.

Regards,
--
Nicolas Ferre


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