BBB MMC / SD detection instability with U-Boot 2014.04 (CPU 1GHz)

[Sulev-Madis Silber (ketas)]

On 2014-05-22 15:58, Sulev-Madis Silber (ketas) wrote:
> On 2014-05-22 14:46, SAITOU Toshihide wrote:
>> In message: <CADH-AwGb36EUknNofdch1Q4Pn8GAN+Ep9SdiJ_f7Q2v9e4kW1g at mail.gmail.com>
>>             Winston Smith <smith.winston.101 at gmail.com> writes:
>>> On Wed, May 21, 2014 at 11:20 AM, SAITOU Toshihide <toshi at ruby.ocn.ne.jp> wrote:
>>>> If abort like
>>>>
>>>>   musbotg0: TI AM335X USBSS v0.0.13
>>>>   Fatal kernel mode data abort: 'External Non-Linefetch Abort (S)'
>>>>   trapframe: 0xc0a2eb60
>>>
>>> I see this with the 1Ghz uboot, it occurs about 50% of the time, see:
>>>
>>> http://comments.gmane.org/gmane.os.freebsd.devel.arm/8200
>>
>> Although it is an ad hoc workaround but ``usb start'' at u-boot command
>> prompt (someone mentioned before) or add device_printf("!\n") before
>> ``rev = USBSS_READ4(sc, USBSS_REVREG);'' in the musbotg_attach of
>> am335x_usbss.c prevent this panic for me.
>>
>> Anyway I understand my procedure is workaround, and is working by
>> chance or side effect, but eMMC boot and 1000 MHz operation is fun.
>>
> 
> 
> I wish I could get that working too... I tried to trace device detection
> path in loader but only found that the problem must be in uboot. Since
> loader is program that runs in uboot. At least now I know how that works
> a bit more. But actual issue remains unresolved. What's weird is how I
> actually boot from eMMC and it's present in uboot... Loader comes from
> eMMC and then loader suddenly has no devices inside it. The hell is that.
> 


Works now... I didn't change code but the way how uboot is configured
through crochet. I think if you want to really piss yourself off then
messing with crochet is good way to do this. I wish those several
versions (normal, devel) of uboot can be added to ports instead (one is
already there), once we get good version. Maybe I should start
maintaining port myself because I hate the situation right now.

Hmm... now, how do I change frequency... lower frequency can be useful
sometimes.