On Mon, 17 Sep 2012, Chris Ball wrote:
> From: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
>
> Previously to this patch, an SDHCI platform that uses a GPIO for
> card detection instead of the internal SDHCI_CARD_PRESENT bit on
> the presence register would fail to bring up a new card because
> logic in sdhci_request() fails the request if that bit is 0.
>
> Some drivers worked around this in various ways: esdhc-imx defines
> an IO accessor to fake the presence bit being true, s3c turns on
> polling (which stops the SDHCI driver from checking the bit) after
> a card's inserted. But none of this should be necessary; the real
> fix is to check whether we're using a GPIO and avoid relying on
> the presence bit if so, as this patch implements.
>
Well, ok, thanks for attributing this patch to me:-) I guess then my Sob
should go in the first, as you'll be forwarding the patch upstream? But
feel free to swap them if you disagree
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
Thanks
Guennadi
> Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index d98b199..0e15c79 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -28,6 +28,7 @@
> #include <linux/mmc/mmc.h>
> #include <linux/mmc/host.h>
> #include <linux/mmc/card.h>
> +#include <linux/mmc/slot-gpio.h>
>
> #include "sdhci.h"
>
> @@ -1293,6 +1294,13 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
> present = sdhci_readl(host, SDHCI_PRESENT_STATE) &
> SDHCI_CARD_PRESENT;
>
> + /* If we're using a cd-gpio, testing the presence bit might fail. */
> + if (!present) {
> + int ret = mmc_gpio_get_cd(host->mmc);
> + if (ret > 0)
> + present = true;
> + }
> +
> if (!present || host->flags & SDHCI_DEVICE_DEAD) {
> host->mrq->cmd->error = -ENOMEDIUM;
> tasklet_schedule(&host->finish_tasklet);
> --
> 1.7.11.2
>
>
>
> - Chris.
> --
> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
> One Laptop Per Child
>
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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