Bisected: omap_hsmmc 3.3V IO voltage incompatible with N900 (Was: Re: Bisected: mmc cause reboot loops on N900)

[Faiz Abbas]

Hi Pali,

On 01/07/20 2:02 pm, Pali Rohár wrote:
> On Friday 12 June 2020 15:03:06 Pali Rohár wrote:
>> On Tuesday 26 May 2020 19:49:54 Pali Rohár wrote:
>>> On Thursday 07 May 2020 17:19:38 Pali Rohár wrote:
>>>> On Thursday 07 May 2020 19:10:14 Faiz Abbas wrote:
>>>>> On 26/04/20 3:59 am, Pali Rohár wrote:
>>>>>> On Sunday 26 April 2020 00:20:07 Pali Rohár wrote:
>>>>>>> On Saturday 25 April 2020 23:26:15 Pali Rohár wrote:
>>>>>>>> Now I tried git bisect and here is problematic commit which caused whole
>>>>>>>> reboot loop:
>>>>>>>>
...
>>>
>>> Hello Faiz!
>>>
>>> Now I figured out what is the root cause of second 3.0V vs 3.3V problem.
>>>
>>> In commit d2c05f50e12f87128597a28146de7092aaa847c3 you forgot to replace
>>> one usage of 3.0V by 3.3V. Below is patch which changes also this last
>>> one usage. Applying it has same effect on Nokia N900 as reverting
>>> that problematic commit d2c05f50e12f87128597a28146de7092aaa847c3:
>>>
>>> diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
>>> index 8636cd713a..dc26e54795 100644
>>> --- a/drivers/mmc/omap_hsmmc.c
>>> +++ b/drivers/mmc/omap_hsmmc.c
>>> @@ -840,7 +840,7 @@ static int omap_hsmmc_init_setup(struct mmc *mmc)
>>>  	omap_hsmmc_conf_bus_power(mmc, (reg_val & VS33_3V3SUP) ?
>>>  			  MMC_SIGNAL_VOLTAGE_330 : MMC_SIGNAL_VOLTAGE_180);
>>>  #else
>>> -	writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V0, &mmc_base->hctl);
>>> +	writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V3, &mmc_base->hctl);
>>>  	writel(readl(&mmc_base->capa) | VS33_3V3SUP | VS18_1V8SUP,
>>>  		&mmc_base->capa);
>>>  #endif
>>>
>>> So eMMC on real N900 is working fine either with 3.0V or 3.3V. But 3.3V
>>> needs to be configured on all places.
>>
>> Hello! Could you please take a look at this issue and my above fix?
> 
> Ping. Any comment for above issue or my fix?
> 

Sorry I missed this earlier. The fix makes sense to me. I can give my reviewed
by to the your fix once you send the patch.

Thanks,
Faiz