[U-Boot] xHCI on x86

[U-Boot] xHCI on x86

[Stefan Roese]

Hi!

I'm currently trying to get xHCI working on some BayTrail based
x86 boards. For this I've added DM support to xhci-pci and made a
small change to cache.h to enable compilation of the xhci driver on
x86 (please find those 2 patches attached - I'll send then to the
list once this is resolved). But I noticed that the xhci driver
hangs in xhci_queue_command() in this line:

	xhci_writel(&ctrl->dba->doorbell[0], DB_VALUE_HOST);

when first writing to the doorbell register. Reading from this doorbell
register still works just fine.

IIRC, Simon has mentioned that xHCI still has some "issues" on x86.
Simon, is this what you have seen as well? Does anyone have some ideas
how to solve this?

Thanks,
Stefan
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[U-Boot] xHCI on x86

[Simon Glass]

Hi,

On 13 July 2016 at 00:20, Stefan Roese <sr@denx.de> wrote:
> Hi!
>
> I'm currently trying to get xHCI working on some BayTrail based
> x86 boards. For this I've added DM support to xhci-pci and made a
> small change to cache.h to enable compilation of the xhci driver on
> x86 (please find those 2 patches attached - I'll send then to the
> list once this is resolved). But I noticed that the xhci driver
> hangs in xhci_queue_command() in this line:
>
>         xhci_writel(&ctrl->dba->doorbell[0], DB_VALUE_HOST);
>
> when first writing to the doorbell register. Reading from this doorbell
> register still works just fine.
>
> IIRC, Simon has mentioned that xHCI still has some "issues" on x86.
> Simon, is this what you have seen as well? Does anyone have some ideas
> how to solve this?

I'm really not sure what is wrong, sorry. The discussion about
enabling the pin settings correctly may be relevant since I believe
two GPIOs need to be set up for both ports to work, and that patch was
never cleaned up and applied, so far as I know...

Regards,
Simon

[U-Boot] xHCI on x86

[Stefan Roese]

Hi Simon,

On 15.07.2016 05:19, Simon Glass wrote:
> On 13 July 2016 at 00:20, Stefan Roese <sr@denx.de> wrote:
>> Hi!
>>
>> I'm currently trying to get xHCI working on some BayTrail based
>> x86 boards. For this I've added DM support to xhci-pci and made a
>> small change to cache.h to enable compilation of the xhci driver on
>> x86 (please find those 2 patches attached - I'll send then to the
>> list once this is resolved). But I noticed that the xhci driver
>> hangs in xhci_queue_command() in this line:
>>
>>          xhci_writel(&ctrl->dba->doorbell[0], DB_VALUE_HOST);
>>
>> when first writing to the doorbell register. Reading from this doorbell
>> register still works just fine.
>>
>> IIRC, Simon has mentioned that xHCI still has some "issues" on x86.
>> Simon, is this what you have seen as well? Does anyone have some ideas
>> how to solve this?
>
> I'm really not sure what is wrong, sorry. The discussion about
> enabling the pin settings correctly may be relevant since I believe
> two GPIOs need to be set up for both ports to work, and that patch was
> never cleaned up and applied, so far as I know...

I see.

I my case, it's not related to the GPIO issue - as the ports are not
enabled via GPIO on the Congatec board where I'm currently testing on.
I've updated the xHCI PCI support a bit (no hangup any more, but still
not working correctly) and will post the current version as WIP today,
as I need to switch to some other tasks for a while. Perhaps someone
else is interested in xHCI on x86 enough to take a look at it in the
meantime...

Thanks,
Stefan