Raspberry Pi Compute Module

[Stephen Warren]

On 08/27/2015 06:44 AM, Martin Sperl wrote:
> On 26.08.2015 15:57, Martin Sperl wrote:
>>> On 24.07.2015, at 05:58, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>>
>>> On 07/22/2015 10:58 AM, Stefan Wahren wrote:
>>>> Hi Stephen,
>>>>
>>>> Am 22.07.2015 um 05:41 schrieb Stephen Warren:
>>>>> On 07/17/2015 11:08 AM, Stefan Wahren wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> is there anyone working on Mainline support for the Compute Module?
>>>>>>
>>>>>> I noticed the downstream kernel already has a bcm2708-rpi-cm.dtsi
>>>>> It is probably close enough that you can simply use bcm2835-rpi-b.dtb
>>>>> for the CM too, for testing at least.
>>>>>
>>>>> I just tried this with latest U-Boot and a 4.2.0-rc3 kernel. The eMMC
>>>>> works fine in U-Boot, but the kernel can't access it for some reason,
>>>>> failing with e.g.:
...
> Compiling the kernel with mmc as module plus mmc-debug enabled gives the
> below:
> after loading the driver:
...
> [   69.432782] mmc0: clock 400000Hz busmode 2 powermode 2 cs 0 Vdd 21
> width 0 timing 0

... lot of working commands ...

> [   69.499732] mmc0: clock 25000000Hz busmode 2 powermode 2 cs 0 Vdd 21
> width 0 timing 0

(up until now, the clock has always be 400KHz, not it's 25MHz)

> [   69.499854] mmc0: starting CMD6 arg 03a10101 flags 0000049d
> [   69.499924] sdhci [sdhci_irq()]: *** mmc0 got interrupt: 0x00038000
> [   69.499982] mmc0: req failed (CMD6): -110, retrying...
> [   69.500041] sdhci [sdhci_irq()]: *** mmc0 got interrupt: 0x00038000
> [   69.500091] mmc0: req failed (CMD6): -110, retrying...
> [   69.500146] sdhci [sdhci_irq()]: *** mmc0 got interrupt: 0x00038000
> [   69.500188] mmc0: req failed (CMD6): -110, retrying...
> [   69.500251] sdhci [sdhci_irq()]: *** mmc0 got interrupt: 0x00038000
> [   69.500300] mmc0: req done (CMD6): -110: 00000000 00000000 00000000
> 00000000
> [   69.500345] mmc0: error -110 whilst initialising MMC card

My guess it that the clock rate change caused this, not the CMD6 itself?