Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752002AbbBKC6R (ORCPT ); Tue, 10 Feb 2015 21:58:17 -0500 Received: from regular1.263xmail.com ([211.150.99.135]:36179 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421AbbBKC6P (ORCPT ); Tue, 10 Feb 2015 21:58:15 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: addy.ke@rock-chips.com X-FST-TO: alim.akhtar@gmail.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: addy.ke@rock-chips.com X-UNIQUE-TAG: <1f08a9dcc625674cdc40dd3f4442f9a7> X-DNS-TYPE: 0 Message-ID: <54DAC534.4020708@rock-chips.com> Date: Wed, 11 Feb 2015 10:57:56 +0800 From: Addy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Alim Akhtar CC: robh+dt , pawel.moll@arm.com, Mark Rutland , ijc+devicetree@hellion.org.uk, galak@codeaurora.org, rdunlap@infradead.org, Seungwon Jeon , Jaehoon Chung , Chris Ball , Ulf Hansson , dinguyen@altera.com, =?UTF-8?B?SGVpa28gU3TDvGJuZXI=?= , Olof Johansson , Douglas Anderson , Sonny Rao , amstan@chromium.org, djkurtz@chromium.org, huangtao@rock-chips.com, "devicetree@vger.kernel.org" , hl@rock-chips.com, linux-doc@vger.kernel.org, yzq@rock-chips.com, zyw@rock-chips.com, zhangqing@rock-chips.com, "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , kever.yang@rock-chips.com, lintao@rock-chips.com, linux-rockchip@lists.infradead.org, xjq@rock-chips.com, zhenfu.fang@rock-chips.com, chenfen@rock-chips.com, cf@rock-chips.com, hj@rock-chips.com, "linux-arm-kernel@lists.infradead.org" , zyf@rock-chips.com Subject: Re: [PATCH v2 1/2] mmc: dw_mmc: fix bug that cause 'Timeout sending command' References: <1423134801-23219-1-git-send-email-addy.ke@rock-chips.com> <1423466726-20833-1-git-send-email-addy.ke@rock-chips.com> <1423466726-20833-2-git-send-email-addy.ke@rock-chips.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4200 Lines: 116 On 2015/02/10 23:22, Alim Akhtar wrote: > Hi Addy, > > On Mon, Feb 9, 2015 at 12:55 PM, Addy Ke wrote: >> Because of some uncertain factors, such as worse card or worse hardware, >> DAT[3:0](the data lines) may be pulled down by card, and mmc controller >> will be in busy state. This should not happend when mmc controller >> send command to update card clocks. If this happends, mci_send_cmd will >> be failed and we will get 'Timeout sending command', and then system will >> be blocked. To avoid this, we need reset mmc controller. >> >> Signed-off-by: Addy Ke >> --- >> drivers/mmc/host/dw_mmc.c | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >> index 4d2e3c2..b0b57e3 100644 >> --- a/drivers/mmc/host/dw_mmc.c >> +++ b/drivers/mmc/host/dw_mmc.c >> @@ -100,6 +100,7 @@ struct idmac_desc { >> }; >> #endif /* CONFIG_MMC_DW_IDMAC */ >> >> +static int dw_mci_card_busy(struct mmc_host *mmc); >> static bool dw_mci_reset(struct dw_mci *host); >> static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset); >> >> @@ -888,6 +889,31 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg) >> cmd, arg, cmd_status); >> } >> >> +static void dw_mci_wait_busy(struct dw_mci_slot *slot) >> +{ >> + struct dw_mci *host = slot->host; >> + unsigned long timeout = jiffies + msecs_to_jiffies(500); >> + > Why 500 msec? This timeout value is the same as mci_send_cmd: static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg) { struct dw_mci *host = slot->host; unsigned long timeout = jiffies + msecs_to_jiffies(500); .... } I have not clear that which is suitable. Do you have any suggestion on it? > >> + do { >> + if (!dw_mci_card_busy(slot->mmc)) >> + return; >> + cpu_relax(); >> + } while (time_before(jiffies, timeout)); >> + >> + dev_err(host->dev, "Data busy (status %#x)\n", >> + mci_readl(slot->host, STATUS)); >> + >> + /* >> + * Data busy, this should not happend when mmc controller send command >> + * to update card clocks in non-volt-switch state. If it happends, we >> + * should reset controller to avoid getting "Timeout sending command". >> + */ >> + dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS); >> + > Why you need to reset all blocks? may be CTRL_RESET is good enough here. I have tested on rk3288, if only reset ctroller, data busy bit will not be cleaned,and we will still get "Timeout sending command". > >> + /* Fail to reset controller or still data busy, WARN_ON! */ >> + WARN_ON(dw_mci_card_busy(slot->mmc)); >> +} >> + >> static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) >> { >> struct dw_mci *host = slot->host; >> @@ -899,6 +925,8 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) >> /* We must continue to set bit 28 in CMD until the change is complete */ >> if (host->state == STATE_WAITING_CMD11_DONE) >> sdmmc_cmd_bits |= SDMMC_CMD_VOLT_SWITCH; >> + else >> + dw_mci_wait_busy(slot); >> > hmm...I would suggest you to call dw_mci_wait_busy() from inside > mci_send_cmd(), seems like dw_mmc hangs while sending update clock cmd > in multiple cases.see [1] > > [1]: http://permalink.gmane.org/gmane.linux.kernel.mmc/31140 I think this patch is more reasonable. So I will resend patches based on this patch. thank you! > >> if (!clock) { >> mci_writel(host, CLKENA, 0); >> -- >> 1.8.3.2 >> >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/