Re: [PATCH 2/5] mmc: dw-mmc: ensure that the card is not busy when changing clock.

[Jaehoon Chung <jh80.chung@samsung.com>]

On 08/23/2012 09:33 PM, Will Newton wrote:
> On Thu, Aug 23, 2012 at 12:31 PM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> To avoid glitches in the card clock output,
>> need to check whether card is busy or not.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
>> ---
>>  drivers/mmc/host/dw_mmc.c |   30 ++++++++++++++++++++++++------
>>  drivers/mmc/host/dw_mmc.h |    1 +
>>  2 files changed, 25 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 36f98c0..8bef3c2 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -623,6 +623,27 @@ static void mci_send_cmd(struct dw_mci_slot *slot, u32 cmd, u32 arg)
>>                 cmd, arg, cmd_status);
>>  }
>>
>> +static void dw_mci_inform_ciu(struct dw_mci_slot *slot)
>> +{
>> +       struct dw_mci *host = slot->host;
>> +       unsigned long timeout = jiffies + msecs_to_jiffies(500);
> 
> Is there a reason why this timeout value was chosen? It seems quite long.
There is no special reason. I will fix it with more reasonable value.
> 
>> +       u32 ctrl, status;
>> +
>> +       do {
>> +               status = mci_readl(host, STATUS);
>> +               if (!(status & SDMMC_DATA_BUSY))
>> +                       break;
>> +               ctrl = mci_readl(host, CTRL);
>> +               ctrl |= SDMMC_CTRL_RESET;
>> +               mci_writel(host, CTRL, ctrl);
>> +       } while (time_before(jiffies, timeout));
>> +
>> +       if (status & SDMMC_DATA_BUSY)
>> +               dev_err(&slot->mmc->class_dev,"Card is busy..!\n");
> 
> The two periods in this message do not need to be there.
Will fix.

Best Regards,
Jaehoon Chung
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