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? 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
