> -----Original Message----- > From: Ulf Hansson [mailto:ulf.hansson@xxxxxxxxxx] > Sent: Thursday, May 28, 2015 4:29 PM > To: Justin Wang (王丁) > Cc: kuninori.morimoto.gx@xxxxxxxxxxx; jh80.chung@xxxxxxxxxxx; > akpm@xxxxxxxxxxxxxxxxxxxx; JBottomley@xxxxxxxx; ben@xxxxxxxxxxxxxxx; > chuanxiao.dong@xxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] mmc: card: Fixup request missing in mmc_blk_issue_rw_rq > Importance: High > > On 19 May 2015 at 08:32, Justin Wang (王丁) <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? > Thanks, I will give a detailed description next patch. > > > > 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. > Yes, process will wait the missed request complete forever, no timeout in block layer. The related process will be blocked. > > > > 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 ��.n��������+%������w��{.n�����{��i��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
