Re: [PATCH 1/2] usb: dwc2: add amcc,dwc-otg support

[Christian Lamparter]

Hello,

On Friday, November 11, 2016 1:22:16 PM CET John Youn wrote:
> On 11/11/2016 12:59 PM, Christian Lamparter wrote:
> > This patch adds support for the "amcc,usb-otg" device
> > which is found in the PowerPC Canyonlands' dts.
> > 
> > The device definition was added by:
> > commit c89b3458d8cc ("powerpc/44x: Add USB DWC DTS entry to Canyonlands board")'
> > but without any driver support as the dwc2 driver wasn't
> > available at that time.
> > 
> > Note: The system can't use the generic "snps,dwc2" compatible
> > because of the special ahbcfg configuration. The default
> > GAHBCFG_HBSTLEN_INCR4 of snps,dwc2 can cause a system hang
> > when the USB and SATA is used concurrently.
> 
> I don't want to add any more of these param structures to the driver
> unless really necessary. We're trying to remove usage of them in favor
> of using auto-detected defaults and device properties to override
> them.
Ok, thanks. I think that would work. I've attached an updated patch.
Can it be applied/queued now? Or do you want me to resent it later?

> The AHB Burst is actually one of the ones we were going to do next
> because our platform also doesn't work well with INCR4. In fact I'm
> thinking of making the default INCR.
Is that actually possible to change the default still? This would
require to re-evaluate all existing archs/platforms that use 
"snps,dwc2" for INCR16 compatibility. 

>From what I can tell based would be:
bcm11351, bcm21664, bcm23550, exynos3250, stm32f429, rk3xxx,
stratix10, meson-gxbb, rt3050 and some Altera FPGAs.

> If that's all you need then a devicetree binding should be enough
> right?
Yes. The device is working fine so far.

Regards,
Christian

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