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

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

Dear, Alim,

Well, I'm not sure that this patch is correct.
But as you mentioned, we need to decide how control the HLE.

I will check the HLE on this weekend. Thanks for your effort.

Best Regards,
Jaehoon Chung

On 11/12/2013 01:12 PM, Alim Akhtar wrote:
> Hi Seungwon/ Jaehoon,
> I can see there are at least three patches which address HLE (Hardware
> Lock Error) in dw_mmc driver.
> 
> https://patchwork.kernel.org/patch/1814991/
> http://www.spinics.net/lists/linux-mmc/msg21459.html
> and third one is my patch
> http://news.gmane.org/gmane.linux.kernel.mmc/cutoff=23010
> 
> Can we have some conclusion about how to handle HLE?
> 
> Thanks!!!
> 
> On Thu, Oct 10, 2013 at 4:31 PM, Alim Akhtar <alim.akhtar@gmail.com> wrote:
>> Hi Jaeohoon,
>>
>> On Mon, Oct 7, 2013 at 2:00 AM, ALIM AKHTAR <alim.akhtar@samsung.com> wrote:
>>> Hi Jaeohoon,
>>> Thanks for quick review.
>>>> ------- Original Message -------
>>>> Sender : Jaehoon Chung<jh80.chung@samsung.com> S4/Engineer/System S/W Lab./Samsung Electronics
>>>> Date : Oct 07, 2013 17:36 (GMT+09:00)
>>>> Title : Re: [PATCH] mmc: dw_mmc: Add hardware lock error (HLE) to the CMD error flag
>>>
>>>> Hi, Alim.
>>>
>>>> On 10/07/2013 05:21 PM, ALIM AKHTAR wrote:
>>>>>
>>>>>
>>>>>> ------- Original Message -------
>>>>>> Sender : Jaehoon Chung 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.
>>> Can you point to the link?
>>>> But we also need to control after occurred the HLE.
>>> Well, dw_mmc controller document just say "The software then has to reload the command" to recover from 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.
>>> HLE is independent of emmc/sd slot and handling should be the same.
>>> Insert/removal is one way to simulate HLE, this is how I found this.
>>> Are you suggesting to check for INT_STATUE for emmc and handle it in case of HLE?
>>
>> Let me know if you have any other comments/ suggestions on this.
>> Thanks!!
>>
>>>>> 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
>>
>> --
>> Regards,
>> Alim
> 
> 
>