[U-Boot] [BUG] 0001-mmc-fix-the-wrong-disabling-clock.patch

[Jaehoon Chung]

On 01/29/2018 09:33 AM, Heinrich Schuchardt wrote:
> On 01/26/2018 07:58 AM, Jaehoon Chung wrote:
>> Hi Heinrich,
>>
>> On 01/26/2018 12:28 PM, Jaehoon Chung wrote:
>>> Hi,
>>>
>>> On 01/26/2018 04:37 AM, Heinrich Schuchardt wrote:
>>>> With git master HEAD the Odroid C2 hangs after the command line countdown.
>>>>
>>>> Bisecting teaches that this is the patch causing the problem:
>>>>
>>>> 9546eb92cb648a8bba0aa9d5930ac751e6e5b9a4
>>>> mmc: fix the wrong disabling clock
>>>
>>> When you search for commit with bisecting, this commit might be occurred a problem.
>>> So i have sent the patches a below patches.
>>>
>>> I don't have odroid-c2 board. so it's difficult to find what happen to your board.
>>> Could you share the log message?
>>>
>>> Almost all boards are working fine. and those patches make sense.
>>>
>>> If revert these patches, too many boards can't use MMC card.
>>>
>>>>
>>>> Please, revert the patch.
>>>
>>> Well, my opinion is first step that we try to find what is main problem about odriod-c2 or others..
>>> Not only revert the patch. Also i will try to solve your issue.
>>
>> I didn't have Odroid-C2 board, i can't test anything. Could you test with below code?
>>
>> diff --git a/drivers/mmc/meson_gx_mmc.c b/drivers/mmc/meson_gx_mmc.c
>> index 3cd934634d..c17efd25c6 100644
>> --- a/drivers/mmc/meson_gx_mmc.c
>> +++ b/drivers/mmc/meson_gx_mmc.c
>> @@ -35,6 +35,9 @@ static void meson_mmc_config_clock(struct mmc *mmc)
>>         uint32_t meson_mmc_clk = 0;
>>         unsigned int clk, clk_src, clk_div;
>>  
>> +       if (mmc->clock == 0)
>> +               return 0;
> 
> You should not return 0 from a void function.
> 
> So, please, write
> 
> 	if (!mmc->clock)
> 		return;

Just for checking your problem.
I didn't have odroid-c2, so i don't know whether it's working fine or not.
Is it working fine?

> 
>> +
>>         /* 1GHz / CLK_MAX_DIV = 15,9 MHz */
>>         if (mmc->clock > 16000000) {
>>                 clk = SD_EMMC_CLKSRC_DIV2;
>>
> 
> Current git HEAD plus this change allows reading from MMC.
> 
> I added a print command and found that the functions is called twice
> with a non-zero value:
> 
> MMC:
> meson_mmc_config_clock: mmc->clock: 380953
> meson_mmc_config_clock: mmc->clock: 380953
> mmc at 72000: 0, mmc at 74000: 1
> 
> But quite a lot of changes have been merged since my first mail, so I am
> not sure which change is relevant.

twice called? In my opinion, meson_gx_mmc is calling mmc_set_clock() in meson_mmc_probe() at probing time.
And after that, mmc_set_clock() is calling at initial time in mmc.c.
So it should be called twice..this is just my thinking.

I want to know that odroid-c2 is working fine or not.?

Best Regards,
Jaehoon Chung

> 
> Best regards
> 
> Heinrich
> 
>> Best Regards,
>> Jaehoon Chung
>>
>>>
>>> Best Regards,
>>> Jaehoon Chung
>>>
>>>>
>>>> I could not find the patch in
>>>> https://lists.denx.de/pipermail/u-boot/2018-January/date.html
>>>>
>>>> http://patchwork.ozlabs.org/patch/864607/
>>>> seems to be related but does not solve the issue.
>>>>
>>>> Best regards
>>>>
>>>> Heinrich
>>>>
>>>>
>>>>
>>>
>>> _______________________________________________
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>>> U-Boot at lists.denx.de
>>> https://lists.denx.de/listinfo/u-boot
>>>
>>
>>
> 
> 
> 
>