Re: [PATCH] mmc: card: Fixup request missing in mmc_blk_issue_rw_rq

[Ulf Hansson]

On 19 May 2015 at 08:32, Justin Wang (çä) <Justin.Wang@xxxxxxxxxxxxxx> wrote:
> From 05849da563c80c20597ab6275d5881a8ed426f96 Mon Sep 17 00:00:00 2001
> From: justin.wang <justin.wang@xxxxxxxxxxxxxx>
> Date: Mon, 18 May 2015 20:14:15 +0800
> Subject: [PATCH] mmc: card: Fixup request missing in mmc_blk_issue_rw_rq
>
> The current handler of MMC_BLK_CMD_ERR in mmc_blk_issue_rw_rq function
> may cause new coming request permanent missing when the ongoing
> request (previoulsy started) complete end.

I think you need to elaborate a bit more here. In exactly what
scenario does this problem occur?

>
> This would cause the process related to the missing request stay at 'D'
> state forever.

'D' state?

I suppose it waits for a response for its IO request. Doesn't also the
block layer complain or timeout somehow? Would be interesting to know
a bit more about what really happens when things goes wrong.

>

Seems like we should have a fixes tag here as well, could you possibly
try to find what commit that introduced this bug?

> Signed-off-by: Ding Wang <justin.wang@xxxxxxxxxxxxxx>
> ---
>  drivers/mmc/card/block.c |    8 +++++---
>  1 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 60f7141..f05cd1f 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1910,9 +1910,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
>                         break;
>                 case MMC_BLK_CMD_ERR:
>                         ret = mmc_blk_cmd_err(md, card, brq, req, ret);
> -                       if (!mmc_blk_reset(md, card->host, type))
> -                               break;
> -                       goto cmd_abort;
> +                       if (mmc_blk_reset(md, card->host, type))
> +                               goto cmd_abort;
> +                       if (!ret)
> +                               goto start_new_req;
> +                       break;
>                 case MMC_BLK_RETRY:
>                         if (retry++ < 5)
>                                 break;
> --
> 1.7.4.1
>

Kind regards
Uffe
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