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. > > Signed-off-by: Addy Ke <addy.ke@xxxxxxxxxxxxxx> Hi Addy, Should I consider $subject patch as a better option to the one below? [PATCH] mmc: dw_mmc: rockchip: Add DW_MCI_QUIRK_RETRY_DELAY 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 linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
