[U-Boot] [PATCH v4] x86: baytrail: Configure FSP UPD from device tree

[Simon Glass]

Hi Bin,

On 10 August 2015 at 20:53, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Andrew,
>
> On Mon, Aug 10, 2015 at 7:32 PM, Andrew Bradford
> <andrew at bradfordembedded.com> wrote:
>> Hi Bin,
>>
>> On 08/09 10:52, Bin Meng wrote:
>>> Hi Andrew,
>>>
>>> On Sun, Aug 9, 2015 at 9:08 AM, Andrew Bradford
>>> <andrew at bradfordembedded.com> wrote:
>>> > Hi Simon,
>>> >
>>> > On 08/08 10:18, Simon Glass wrote:
>>> >> Hi,
>>> >>
>>> >> On 7 August 2015 at 06:44, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> >> > On Fri, Aug 7, 2015 at 8:36 PM, Andrew Bradford
>>> >> > <andrew at bradfordembedded.com> wrote:
>>> >> >> From: Andrew Bradford <andrew.bradford at kodakalaris.com>
>>> >> >>
>>> >> >> Allow for configuration of FSP UPD from the device tree which will
>>> >> >> override any settings which the FSP was built with itself.
>>> >> >>
>>> >> >> Modify the MinnowMax and BayleyBay boards to transfer sensible UPD
>>> >> >> settings from the Intel FSPv4 Gold release to the respective dts files,
>>> >> >> with the condition that the memory-down parameters for MinnowMax are
>>> >> >> also used.
>>> >> >>
>>> >> >> Signed-off-by: Andrew Bradford <andrew.bradford at kodakalaris.com>
>>> >> >> ---
>>> >> >>
>>> >> >
>>> >> > Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
>>> >> > Tested-by: Bin Meng <bmeng.cn at gmail.com>
>>> >> >
>>> >>
>>> >> Acked-by: Simon Glass <sjg at chromium.org>
>>> >> Tested on minnowmax:
>>> >> Tested-by: Simon Glass <sjg at chromium.org>
>>> >>
>>> >> I found that I need to remove two properties from the minnowmax.dts:
>>> >>
>>> >> - fsp,enable-xhci needs to be removed as this does not work in U-Boot
>>> >> at present and stops EHCI from working
>>> >> - fsp,mrc-debug-msg needs to be removed to prevent debug information
>>> >> being displayed
>>> >>
>>> >> I plan to apply this with these changes - please let me know if this
>>> >> doesn't suit.
>>> >
>>> > I'm OK with disabling xhci and the MRC debug output in the FSP.
>>> >
>>> > But if xhci is disabled then I believe when Linux boots that the USB 3.0
>>> > port on Minnow Max will only act as a USB 2.0 port.  That u-boot doesn't
>>> > yet have working XHCI on E3800 means there is a tradeoff and I wasn't
>>> > sure which was a better choice.
>>>
>>> Does these xHCI ports on MinnowMax work fully on Linux kernel? If it
>>> works, I'd rather we keep fsp,enable-xhci in the U-Boot.
>>
>> I believe that the xhci port does work on Minnow Max in Linux but I do
>> not have a board so I'm unable to test, sorry.
>>
>
> OK, my test shows that ehci works fine in U-Boot on Bayley Bay.
>
> Hi Simon,
>
> What do you think regarding to xhci vs. ehci in U-Boot?

The problem is that USB is then broken in U-Boot. I think it is better
to limit the speed for the moment until we have that fixed. It is
quite useful to be able to use a keyboard or USB stick in U-Boot.

With my testing the bottom (blue) port works fine but the top port
does not. This happens regardless of the xhci setting.

So overall I think we are in a better position to go with ehci for
now, i.e. drop the fsp,enable-xhci property.

I think there is a little tweak needed to support both ports, but I
haven't dug into it yet.

Regards,
Simon