Re: [PATCH] mmc: dw_mmc: clear INSTS register when initialize

Joonyoung Shim
2013-04-24T03:05:25Z

On 04/24/2013 10:34 AM, Seungwon Jeon wrote:
> On Tuesday, April 23, 2013, Jaehoon Chung wrote:
>> On 04/23/2013 06:57 PM, Seungwon Jeon wrote:
>>> Hi,
>>>
>>> On Thursday, April 18, 2013, Joonyoung Shim wrote:
>>>> If pending interrupt for IDMAC exists when probe, it will call interrupt
>>>> handler unnecessarily.
>>>>
>>>> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
>>>> ---
>>>> drivers/mmc/host/dw_mmc.c | 3 +++
>>>> 1 file changed, 3 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index 323c502..b0057a2 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -2192,6 +2192,7 @@ int dw_mci_probe(struct dw_mci *host)
>>>>
>>>> /* Clear the interrupts for the host controller */
>>>> mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>> + mci_writel(host, IDSTS, 0xFFFFFFFF);
>>> 0x337 is correct for bits. Could you check the bit filed?

I feel it's better to use already existing defines than 0x337.

>> I think that don't care which reset value used.
>> "It is recommended that you write 0xffff_ffff to the Raw Interrupt register @0x044 and IDSTS @0x8C
>> in order to clear any pending interrupts before setting the int_enable bit."
>> This boot mode case is also used the 0xffff_ffff.

Jaehoon, can i get this sentence from which document?

> In case IDSTS all 32bit are not for interrupt status unlike RINTSTS.
> IDSTS[31:17] is reserved and IDSTS[16:0] also contains 'reserved' and 'read-only' field.
> Correct use would be needed.
>
> Thanks,
> Seungwon Jeon
>>>> mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
>>>>
>>>> /* Put in max timeout */
>>>> @@ -2243,6 +2244,7 @@ int dw_mci_probe(struct dw_mci *host)
>>>> * receive ready and error such as transmit, receive timeout, crc error
>>>> */
>>>> mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>> + mci_writel(host, IDSTS, 0xFFFFFFFF);
>>> No need, it's already done above.

OK.

>>>
>>>> mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
>>>> SDMMC_INT_TXDR | SDMMC_INT_RXDR |
>>>> DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
>>>> @@ -2393,6 +2395,7 @@ int dw_mci_resume(struct dw_mci *host)
>>>> mci_writel(host, FIFOTH, host->fifoth_val);
>>>>
>>>> mci_writel(host, RINTSTS, 0xFFFFFFFF);
>>>> + mci_writel(host, IDSTS, 0xFFFFFFFF);
>>> Same, incorrect bits.
>>>
>>> Thanks,
>>> Seungwon Jeon
>>>
>>>> mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
>>>> SDMMC_INT_TXDR | SDMMC_INT_RXDR |
>>>> DW_MCI_ERROR_FLAGS | SDMMC_INT_CD);
>>>> --
>>>> 1.7.9.5
>>>>
>>>> --
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>>>

Thanks.