Re: [PATCH] mmc: mxs: fix card detection in case of 'broken-cd' flag set

From: Sascha Hauer
Date: Mon Jul 07 2014 - 02:28:17 EST


On Tue, Jun 10, 2014 at 11:57:02PM +0900, Roman Pen wrote:
> In case of reboot my olinuxino imx23 board does not see
> mmc card any more. mmc_rescan is being called by delayed
> work in loop, but mxs_mmc_get_cd always returns 0, so we
> will never pass the card detection check and will not do
> further card inition.
>
> This patch is just an attempt to partially revert the patch
> a91fe279ae of Sascha Hauer, where it is claimed that upper
> layer will handle broken card detection using the polling
> logic and MMC_CAP_NEEDS_POLL capability, but seems it is not
> true, because upper logic still expects 1 from 'get_cd'.
>
> So, here we always return 1 (card present) in case of
> MMC_CAP_NEEDS_POLL capability set.
>
> Signed-off-by: Roman Pen <r.peniaev@xxxxxxxxx>
> CC: Chris Ball <chris@xxxxxxxxxx>
> CC: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> CC: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
> CC: Shawn Guo <shawn.guo@xxxxxxxxxx>
> CC: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> CC: linux-mmc@xxxxxxxxxxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx

I still didn't find the time to take a proper look at it. Since this
fixes a bug for you:

Acked-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>

Sascha

> ---
> drivers/mmc/host/mxs-mmc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
> index 073e871..9187ce1 100644
> --- a/drivers/mmc/host/mxs-mmc.c
> +++ b/drivers/mmc/host/mxs-mmc.c
> @@ -82,7 +82,8 @@ static int mxs_mmc_get_cd(struct mmc_host *mmc)
> if (ret >= 0)
> return ret;
>
> - present = !(readl(ssp->base + HW_SSP_STATUS(ssp)) &
> + present = mmc->caps & MMC_CAP_NEEDS_POLL ||
> + !(readl(ssp->base + HW_SSP_STATUS(ssp)) &
> BM_SSP_STATUS_CARD_DETECT);
>
> if (mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH)
> --
> 1.9.1
>
>

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