On 2015/2/9 15:04, Jaehoon Chung wrote: > On 02/09/2015 03:56 PM, Addy wrote: >> >> >> On 2015.02.09 12:51, Ulf Hansson wrote: >>> On 5 February 2015 at 12:13, Addy Ke <addy.ke@xxxxxxxxxxxxxx> 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. > > I know that it needs to check whether card is busy or not, before clock-off. > This patch seems to related with it. right? Yes, it is. > > Best Regards, > Jaehoon Chung > >>>> >>>> Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx> >>> >>> Hi Addy, >>> >>> Should I consider $subject patch as a better option to the one below? >> No: >> This patch fix the bug, which can be found by script: >> cd /sys/bus/platform/drivers/dwmmc_rockchip >> for i in $(seq 1 10000); do >> echo "========================" $i >> echo ff0c0000.dwmmc > unbind >> sleep .5 >> echo ff0c0000.dwmmc > bind >> sleep 2 >> done >> >>> [PATCH] mmc: dw_mmc: rockchip: Add DW_MCI_QUIRK_RETRY_DELAY >> This patch is for tuning issue: we should delay until card go to idle state, when the previous command return error. >>> https://lkml.org/lkml/2015/1/13/562 >>> >>> Kind regards >>> Uffe >>> >>> >>>> --- >>>> drivers/mmc/host/dw_mmc.c | 23 +++++++++++++++++++++++ >>>> 1 file changed, 23 insertions(+) >>>> >>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>>> index 4d2e3c2..b1d6dfb 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 +889,26 @@ 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); >>>> + >>>> + while (time_before(jiffies, timeout)) { >>>> + if (!dw_mci_card_busy(slot->mmc)) >>>> + return; >>>> + } >>>> + 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); >>>> +} >>>> + >>>> static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) >>>> { >>>> struct dw_mci *host = slot->host; >>>> @@ -899,6 +920,8 @@ 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); >>>> >>>> if (!clock) { >>>> mci_writel(host, CLKENA, 0); >>>> -- >>>> 1.8.3.2 >>>> >>>> >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in >>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>> >> >> >> > > > > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
