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

Pierre Ossman
2008-11-14T21:41:29Z

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?

> +
> + /* 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.

> +
> + 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.

> +#define SDHCI_DATA_BIT(x) (1 << ((x) + 20))

This was not supposed to be included I suppose :)

Rgds
--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
rdesktop, core developer http://www.rdesktop.org

WARNING: This correspondence is being monitored by the
Swedish government. Make sure your server uses encryption
for SMTP traffic and consider using PGP for end-to-end
encryption.