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

Joonyoung Shim
2013-04-25T07:48:55Z

On 04/25/2013 09:45 AM, Jaehoon Chung wrote:
> On 04/24/2013 12:05 PM, Joonyoung Shim wrote:
>> 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?
> That comment is existed at "Synopsys DesignWare Cores mobile storage host databook".
> So we can use the 0xffff_ffff.
>
> Best Regards,
> Jaehoon Chung
>>> 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.

I know, but as Jaehoon said, it recommands to write 0xFFFFFFFF "Synopsys
DesignWare Cores mobile storage host databook" document, so i also think
it's ok.

Nevertheless if you want to use strict bits set, i can modify it. What
is your idea?

Thanks.