On Thursday, November 08, 2012, Jaehoon Chung <jh80.ch...@samsung.com> wrote:
> Before disabling clock, need to check whether card is busy on not.
>
> Signed-off-by: Jaehoon Chung <jh80.ch...@samsung.com>
> ---
> 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())
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
> --
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