Re: [patch 4/7] SDHCI: Add quirk for controller with no end-of-busy IRQ

Ben Dooks
2008-11-15T23:59:00Z

On Fri, Nov 14, 2008 at 10:41:14PM +0100, Pierre Ossman wrote:
> On Mon, 03 Nov 2008 20:09:48 +0000
> Ben Dooks <ben-linux@fluff.org> wrote:
>
> > The Samsung SDHCI controller block seems to fail to generate an
> > INT_DATA_END after the transfer has completed and the bus busy
> > state finished.
> >
> > Changes in e809517f6fa5803a5a1cd56026f0e2190fc13d5c to use the
> > new busy method are the cause of the behaviour change.
> >
> > Signed-off-by: Ben Dooks <ben-linux@fluff.org>
> >
> > Index: linux.git/drivers/mmc/host/sdhci.c
> > ===================================================================
> > --- linux.git.orig/drivers/mmc/host/sdhci.c 2008-11-03 10:01:03.000000000 +0000
> > +++ linux.git/drivers/mmc/host/sdhci.c 2008-11-03 12:20:40.000000000 +0000
> > @@ -1291,11 +1291,24 @@ static void sdhci_cmd_irq(struct sdhci_h
> > * controllers.
> > */
> > if (host->cmd->flags & MMC_RSP_BUSY) {
> > + u32 present;
> > +
> > if (host->cmd->data)
> > DBG("Cannot wait for busy signal when also "
> > "doing a data transfer");
> > - else
> > + else if (!(host->quirks & SDHCI_QUIRK_NO_TCIRQ_ON_NOT_BUSY))
> > return;
>
> Not the clearest naming I've ever seen. :)
> How about NO_BUSY_IRQ?

ok, will change.

> > +
> > + /* The Samsung SDHCI does not seem to provide an INT_DATA_END
> > + * when the system goes non-busy, so check the state of the
> > + * transfer by reading SDHCI_PRESENT_STATE to see if the
> > + * controller is ready
> > + */
>
> There is already a note about this being a problem earlier up, so I
> don't think we need another.

right.

> > +
> > + present = readl(host->ioaddr + SDHCI_PRESENT_STATE);
> > + DBG("busy? present %08x, intstat %08x\n", present, intmask);
> > +
>
> And what does this add really? Controllers not being able to wait for
> the busy state to end is so common that we can just ignore the problem
> here.
>

that was debug.

> > +#define SDHCI_DATA_BIT(x) (1 << ((x) + 20))
>
> This was not supposed to be included I suppose :)

was with teh debug.