Re: [PATCH v2 3/4] mmc: dw_mmc: Convert to mmc_send_tuning()

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

Hi, Alim.

On 12/20/2014 10:34 PM, Alim Akhtar wrote:
> Hi Jaehoon
> 
> On Mon, Dec 15, 2014 at 10:18 AM, Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi, Alim.
>>
>> On 12/13/2014 12:13 AM, Jaehoon Chung wrote:
>>> Hi.
>>>
>>> On 12/10/2014 06:30 AM, Alim Akhtar wrote:
>>>> Hi Ulf
>>>>
>>>> On Mon, Dec 8, 2014 at 3:40 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>>>> On 6 December 2014 at 13:43, Alim Akhtar <alim.akhtar@gmail.com> wrote:
>>>>>> Hi Ulf,
>>>>>>
>>>>>> On Fri, Dec 5, 2014 at 5:29 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>>>>>> Instead of having a local hack taking care of sending the tuning
>>>>>>> command and as well to verify the response pattern, let's convert to
>>>>>>> the common mmc_send_tuning() API.
>>>>>>>
>>>>>>> This change affects the Exynos variant, since it's the only one which
>>>>>>> support the dw_mmc's ->execute_tuning() callback.
>>>>>>>
>>>>>>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>>>>>>> ---
>>>>>>>
>>>>>
>>>>> Alim, thanks for helping out testing!
>>>>>
>>>> Sorry for the delay but currently I don't have access to my work station.
>>>> And thanks for quick suggested patch, I will test this as soon asI go
>>>> back to my work.
>>>>
>>>> Hi Jaehoon, can you test this and the original patch for hs200 on
>>>> exynos? Just to confirm my board is not the special one.
>>>> Thanks.
>>>
>>> Does it need to send "stop command" at exynos5800?
>>> Well, most SoC doesn't need to send stop command, also exynos.
>>> But i will check other exynos boards..then i will share result.
>>>
>>> Best Regards,
>>> Jaehoon Chung
>>>
>>>>
>>>>>> With this change HS200 mode does not work on exynos5800 peach-pi board.
>>>>>> I got below error while testing this series:
>>>>>>
>>>>>> mmc0: tuning execution failed
>>>>>> mmc0: error -5 whilst initialising MMC card
>>
>> Did you share the CLKSEL register value?
> 
> CLKSEL value remain same in failed and pass case (in my case it is
> 0x0304000x, x is for sample phases)

Thanks for share the value. i will check it.

> 
>> I think exynos SoC didn't need to send stop command.
>> (I didn't find the STOP command is completed when tuning sequence.)
>> When i have tested, according to SELCLK_DRV value, tuning results were changed.
>>
> Did you tested on exynos5?

Sure, I have tested on exynos5. It's working well without stop command.

>> if you got the above error, i recommend you can change the SELCLK_DRV value.
>>
> I did tried changing that but didn't helped, but not tried all
> combinations though, I can recheck this again.

Right. there is too many combinations..so i also didn't check all combinations.
Did you enable the Debugging message for mmc?

Best Regards,
Jaehoon Chung

> 
>> Best Regards,
>> Jaehoon Chung
>>
>>>>>>
>>>>>> Though, your's next branch with commit _a1d06b4_ works fine in HS200 mode.
>>>>>
>>>>> I was looking into the details of what change my patchset introduces
>>>>> for dw_mmc-exynos. Apparently, dw_mmc-exynos was using the
>>>>> MMC_STOP_TRANSMISSION to end the tuning reqeust (CMD21/19). The new
>>>>> mmc_send_tuning() API doesn't, which also conforms to what the eMMC/SD
>>>>> specifications states.
>>>>>
>>>>> Do you have any idea of why dw_mmc-exynos was using
>>>>> MMC_STOP_TRANSMISSION for CMD19/21?
>>>>>
>>>>> To see if my theory is correct, could you try out the following patch
>>>>> on top of $subject patch?
>>>>> BTW, I have queued patch 1 and 2, from this patchset available on my
>>>>> next branch.
>>>>>
>>>>>
>>>>> From e1ac35bb0e90254275ec7088f41e6e2d59e48367 Mon Sep 17 00:00:00 2001
>>>>> From: Ulf Hansson <ulf.hansson@linaro.org>
>>>>> Date: Mon, 8 Dec 2014 10:58:48 +0100
>>>>> Subject: [PATCH] mmc: core: End tuning request with stop command
>>>>>
>>>>> Not to be merged!
>>>>>
>>>>> This patch adds the MMC_STOP_TRANSMISSION command to end a tuning
>>>>> request. For some reason dw_mmc seems to need this to complete the
>>>>> tuning request without errors.
>>>>>
>>>>> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
>>>>> ---
>>>>>  drivers/mmc/core/mmc_ops.c | 5 +++++
>>>>>  1 file changed, 5 insertions(+)
>>>>>
>>>>> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
>>>>> index 3b044c5..aa79e0c 100644
>>>>> --- a/drivers/mmc/core/mmc_ops.c
>>>>> +++ b/drivers/mmc/core/mmc_ops.c
>>>>> @@ -551,6 +551,7 @@ int mmc_send_tuning(struct mmc_host *host)
>>>>>  {
>>>>>         struct mmc_request mrq = {NULL};
>>>>>         struct mmc_command cmd = {0};
>>>>> +       struct mmc_command stop = {0};
>>>>>         struct mmc_data data = {0};
>>>>>         struct scatterlist sg;
>>>>>         struct mmc_ios *ios = &host->ios;
>>>>> @@ -576,10 +577,14 @@ int mmc_send_tuning(struct mmc_host *host)
>>>>>
>>>>>         mrq.cmd = &cmd;
>>>>>         mrq.data = &data;
>>>>> +       mrq.stop = &stop;
>>>>>
>>>>>         cmd.opcode = opcode;
>>>>>         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
>>>>>
>>>>> +       stop.opcode = MMC_STOP_TRANSMISSION;
>>>>> +       stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
>>>>> +
>>>>>         data.blksz = size;
>>>>>         data.blocks = 1;
>>>>>         data.flags = MMC_DATA_READ;
>>>>> --
>>>>> 1.9.1
>>>>>
>>>>> Kind regards
>>>>> Uffe
>>>>
>>>>
>>>>
>>>
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>>
> 
> 
>