Re: [PATCH] mmc: dw_mmc: Add hardware lock error (HLE) to the CMD error flag

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

Hi, Alim.

On 10/07/2013 05:21 PM, ALIM AKHTAR wrote:
> 
> 
>> ------- Original Message -------
>> Sender : Jaehoon Chung<jh80.chung@samsung.com> S4/Engineer/System S/W Lab./Samsung Electronics
>> Date : Oct 07, 2013 13:34 (GMT+09:00)
>> Title : Re: [PATCH] mmc: dw_mmc: Add hardware lock error (HLE) to the CMD error flag
> 
>> On 10/07/2013 01:22 PM, ALIM AKHTAR wrote:
>>> Hi Jaehoon,
>>>
>>>> ------- Original Message -------
>>>> Sender : Jaehoon Chung S4/Engineer/System S/W Lab./Samsung Electronics
>>>> Date : Oct 06, 2013 17:28 (GMT+09:00)
>>> Title : Re: [PATCH] mmc: dw_mmc: Add hardware lock error (HLE) to the CMD error flag
>>  
>>> Hi Alim,
>>
>>> On 10/03/2013 06:18 PM, alim akhtar wrote:
>>>> From: Alim Akhtar 
>>>>
>>>> Hardware locked error set when the dw_mmc controller cannot load a
>>>> command issued by software. When software sets the start_cmd bit in the
>>>> CMD register, the controller tries to load the command. If the command
>>>> buffer is already filled with a command, this error is raised. Currently
>>>> driver does not handle HLE interrupt, which results in a system hang.
>>> When SDMMC_INT_HLE is set into CMD_ERROR_FLAGS,.then could driver handle the HLE interrupt?
>> Yes, this will be handled as a part of DW_MCI_CMD_ERROR_FLAGS error handling.
>> Could some command or data be lost?
> No, Data and command will not be lost as they are not send out.
Maybe it needs to discuss how recovery the command/data, when HLE interrupt is occured.
I want to know, do you have the recovery method when HLE interrupt is occured?

As you mentioned, this patch controlled the HLE error and can't send the any command/data.
Patch like this had already posted at mailing list.
But we also need to control after occurred the HLE.

In SD-card's case, card can be inserted/removed. but in case of eMMC, can't it.
It should be maintained the hardware lock status.

Best Regards,
Jaehoon Chung

>>>
>>>> Best Regards,
>>>> Jaehoon Chung
>>>>
>>>> HLE can be simulated by quickly inserting and removing sd card in card
>>>> slot (30 ~ 40 times in say 20 secs)
>>>>
>>>> Reviewed-by: Doug Anderson 
>>>> Signed-off-by: Alim Akhtar 
>>>> ---
>>>>   drivers/mmc/host/dw_mmc.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index 0a6a512..24b4a52 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -44,7 +44,7 @@
>>>>   SDMMC_INT_HTO | SDMMC_INT_SBE  | \
>>>>   SDMMC_INT_EBE)
>>>>   #define DW_MCI_CMD_ERROR_FLAGS (SDMMC_INT_RTO | SDMMC_INT_RCRC | \
>>>> - SDMMC_INT_RESP_ERR)
>>>> + SDMMC_INT_RESP_ERR | SDMMC_INT_HLE)
>>>>   #define DW_MCI_ERROR_FLAGS (DW_MCI_DATA_ERROR_FLAGS | \
>>>>   DW_MCI_CMD_ERROR_FLAGS  | SDMMC_INT_HLE)
>>>>   #define DW_MCI_SEND_STATUS 1
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