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

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Hi Jaehoon

On Mon, Dec 15, 2014 at 10:18 AM, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> 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@xxxxxxxxxx> wrote:
>>>> On 6 December 2014 at 13:43, Alim Akhtar <alim.akhtar@xxxxxxxxx> wrote:
>>>>> Hi Ulf,
>>>>>
>>>>> On Fri, Dec 5, 2014 at 5:29 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> 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@xxxxxxxxxx>
>>>>>> ---
>>>>>>
>>>>
>>>> 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)

> 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?
> 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.

> 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@xxxxxxxxxx>
>>>> 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@xxxxxxxxxx>
>>>> ---
>>>>  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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>



-- 
Regards,
Alim
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