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

[SAITOU Toshihide]

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.

-- 
SAITOU Toshihide