On 11/27/2012 05:02 PM, Seungwon Jeon wrote:
> 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())
Is there reason that use "usleep_range()"?
>
> 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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