2012/11/28 Seungwon Jeon <tgih.jun@xxxxxxxxxxx>: > On Wednesday, November 28, 2012, Jaehoon Chung wrote: >> On 11/27/2012 05:02 PM, Seungwon Jeon wrote: >> > On Thursday, November 08, 2012, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: >> >> Before disabling clock, need to check whether card is busy on not. >> >> >> >> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> >> >> --- >> >> drivers/mmc/host/dw_mmc.c | 53 +++++++++++++++++++++++++++----------------- >> >> drivers/mmc/host/dw_mmc.h | 1 + >> >> 2 files changed, 33 insertions(+), 21 deletions(-) >> >> >> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >> >> index 0a80b5c..9704b09 100644 >> >> --- a/drivers/mmc/host/dw_mmc.c >> >> +++ b/drivers/mmc/host/dw_mmc.c >> >> @@ -228,6 +228,27 @@ static void dw_mci_set_timeout(struct dw_mci *host) >> >> mci_writel(host, TMOUT, 0xffffffff); >> >> } >> >> >> >> +static bool mci_wait_reset(struct device *dev, struct dw_mci *host) >> >> +{ >> >> + unsigned long timeout = jiffies + msecs_to_jiffies(500); >> >> + unsigned int ctrl; >> >> + >> >> + mci_writel(host, CTRL, (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | >> >> + SDMMC_CTRL_DMA_RESET)); >> >> + >> >> + /* wait till resets clear */ >> >> + do { >> >> + ctrl = mci_readl(host, CTRL); >> >> + if (!(ctrl & (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | >> >> + SDMMC_CTRL_DMA_RESET))) >> >> + return true; >> >> + } while (time_before(jiffies, timeout)); >> >> + >> >> + dev_err(dev, "Timeout resetting block (ctrl %#x)\n", ctrl); >> >> + >> >> + return false; >> >> +} >> >> + >> >> static u32 dw_mci_prepare_command(struct mmc_host *mmc, struct mmc_command *cmd) >> >> { >> >> struct mmc_data *data; >> >> @@ -622,6 +643,7 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) >> >> struct dw_mci *host = slot->host; >> >> u32 div; >> >> u32 clk_en_a; >> >> + int timeout = 1000; >> >> >> >> if (slot->clock != host->current_speed) { >> >> div = host->bus_hz / slot->clock; >> >> @@ -638,6 +660,16 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot) >> >> "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ" >> >> " div = %d)\n", slot->id, host->bus_hz, slot->clock, >> >> div ? ((host->bus_hz / div) >> 1) : host->bus_hz, div); >> >> + do { >> >> + if (!(mci_readl(host, STATUS) & SDMMC_DATA_BUSY)) >> >> + break; >> >> + if (timeout-- < 0) { >> >> + dev_err(host->dev, "Can't disable clock" >> >> + "because Card is busy!!\n"); >> >> + return; >> >> + } >> >> + mci_wait_reset(host->dev, host); >> > Should 'mci_wait_reset' be called every loop? >> > Only if card status is still busy at the end of while, one time is enough. >> > >> >> + } while (1); >> > How about counting jiffies for while-loop with usleep_range? >> > do { >> > ... >> > usleep_range(10, 20) >> > } while (time_before()) >> Is there reason that use "usleep_range()"? > If we should wait busy status with long time, > it would be better sleep-wait rather than just busy-wait. Thank you for review. well..it will use the sleep-wait. why use the 10~20? just example? Then i will check this and resend the patch. Best Regards, Jaehoon Chung > > Thanks, > Seungwon Jeon >> > >> > Thanks, >> > Seungwon Jeon >> >> >> >> /* disable clock */ >> >> mci_writel(host, CLKENA, 0); >> >> @@ -1995,27 +2027,6 @@ no_dma: >> >> return; >> >> } >> >> >> >> -static bool mci_wait_reset(struct device *dev, struct dw_mci *host) >> >> -{ >> >> - unsigned long timeout = jiffies + msecs_to_jiffies(500); >> >> - unsigned int ctrl; >> >> - >> >> - mci_writel(host, CTRL, (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | >> >> - SDMMC_CTRL_DMA_RESET)); >> >> - >> >> - /* wait till resets clear */ >> >> - do { >> >> - ctrl = mci_readl(host, CTRL); >> >> - if (!(ctrl & (SDMMC_CTRL_RESET | SDMMC_CTRL_FIFO_RESET | >> >> - SDMMC_CTRL_DMA_RESET))) >> >> - return true; >> >> - } while (time_before(jiffies, timeout)); >> >> - >> >> - dev_err(dev, "Timeout resetting block (ctrl %#x)\n", ctrl); >> >> - >> >> - return false; >> >> -} >> >> - >> >> #ifdef CONFIG_OF >> >> static struct dw_mci_of_quirks { >> >> char *quirk; >> >> diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h >> >> index 53b8fd9..4f27357 100644 >> >> --- a/drivers/mmc/host/dw_mmc.h >> >> +++ b/drivers/mmc/host/dw_mmc.h >> >> @@ -127,6 +127,7 @@ >> >> #define SDMMC_CMD_INDX(n) ((n) & 0x1F) >> >> /* Status register defines */ >> >> #define SDMMC_GET_FCNT(x) (((x)>>17) & 0x1FFF) >> >> +#define SDMMC_DATA_BUSY BIT(9) >> >> /* Internal DMAC interrupt defines */ >> >> #define SDMMC_IDMAC_INT_AI BIT(9) >> >> #define SDMMC_IDMAC_INT_NI BIT(8) >> >> -- >> >> 1.7.4.1 >> >> -- >> >> 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-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-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-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-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html