Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752234AbcDVMYs (ORCPT ); Fri, 22 Apr 2016 08:24:48 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:34847 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbcDVMYq (ORCPT ); Fri, 22 Apr 2016 08:24:46 -0400 MIME-Version: 1.0 In-Reply-To: <1460963609-16179-1-git-send-email-chaotian.jing@mediatek.com> References: <1460963609-16179-1-git-send-email-chaotian.jing@mediatek.com> Date: Fri, 22 Apr 2016 14:24:44 +0200 Message-ID: Subject: Re: [PATCH] mmc: mediatek: fix request blocked by cancel_delayed_work From: Ulf Hansson To: Chaotian Jing Cc: Matthias Brugger , Nicolas Boichat , Douglas Anderson , Geert Uytterhoeven , linux-mmc , "linux-arm-kernel@lists.infradead.org" , linux-mediatek@lists.infradead.org, "linux-kernel@vger.kernel.org" , srv_heupstream , Sascha Hauer Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2771 Lines: 72 On 18 April 2016 at 09:13, Chaotian Jing wrote: > there are 2 points will cause could not call mmc_request_done() > and eventually cause the caller thread blocked. > > A. if card was busy, cancel_delayed_work() will return false because > the delay work has not been scheduled, in this case, need put > mod_delayed_work() in front of msdc_cmd_is_ready() > > B. if a request really need more than 5s(Some Sandisk TF card), it will > use cancel_delayed_work() to cancel itself, and also return false, so use > in_interrupt() to avoid this case > > Signed-off-by: Chaotian Jing > --- > drivers/mmc/host/mtk-sd.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c > index b17f30d..1511b1b 100644 > --- a/drivers/mmc/host/mtk-sd.c > +++ b/drivers/mmc/host/mtk-sd.c > @@ -724,7 +724,7 @@ static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq) > bool ret; > > ret = cancel_delayed_work(&host->req_timeout); > - if (!ret) { > + if (!ret && in_interrupt()) { > /* delay work already running */ > return; > } > @@ -824,7 +824,12 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host, > } > > if (mmc_resp_type(cmd) == MMC_RSP_R1B || cmd->data) { > - tmo = jiffies + msecs_to_jiffies(20); > + /* > + * 2550ms is from EXT_CSD[248], after switch to hs200, > + * using CMD13 to polling card status, it will get response > + * of 0x800, but EMMC still pull-low DAT0. > + */ Seems like you are solving a eMMC specific issue on your driver? Perhaps we should try to use a card quirk instead? > + tmo = jiffies + msecs_to_jiffies(2550); > /* R1B or with data, should check SDCBUSY */ > while ((readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) && > time_before(jiffies, tmo)) > @@ -847,6 +852,7 @@ static void msdc_start_command(struct msdc_host *host, > WARN_ON(host->cmd); > host->cmd = cmd; > > + mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT); > if (!msdc_cmd_is_ready(host, mrq, cmd)) > return; > > @@ -858,7 +864,6 @@ static void msdc_start_command(struct msdc_host *host, > > cmd->error = 0; > rawcmd = msdc_cmd_prepare_raw_cmd(host, mrq, cmd); > - mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT); > > sdr_set_bits(host->base + MSDC_INTEN, cmd_ints_mask); > writel(cmd->arg, host->base + SDC_ARG); > -- > 1.8.1.1.dirty > Kind regards Uffe