Re: [RESEND PATCH] usb: chipidea: Configure DMA properties and ops from DT

[Bjorn Andersson]

On Fri 21 Oct 10:38 PDT 2016, Stephen Boyd wrote:

> On 10/21, Bjorn Andersson wrote:
> > hcd_alloc_coherent() and usb_alloc_coherent() ends up allocating coherent
> > memory on behalf of ci_hdrc driver. But as the ci_hdrc is instantiated manually
> > it will not have any dma_mem or dma_ops assigned, which makes the
> > dma_alloc_coherent() fail on some platforms (e.g. arm64). This patch solves
> > this by assigning the dma_mem and dma_ops based on the parent's DeviceTree
> > node.
> > 
> > Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > ---
> > 
> > Hi Peter,
> > 
> > After (once more) debugging why USB doesn't work up on the 64-bit Qualcomm
> > systems I realized that we never concluded on this patch. Unfortunately I can't
> > find it in my mailbox either, so resending it to restart the discussion.
> > 
> 
> I thought we were going to go down the route that Arnd has been
> pushing[1]? That should work, but I haven't tried it yet and
> there are some more fixes on top from Sriram. I think Sriram is
> taking over the patch now?
> 
> [1] https://patchwork.kernel.org/patch/9319527/

Thanks for the pointer, I've heard about it but couldn't find it.

It does make me further wonder about the multi-device model of these
drivers, but I agree with you that it looks like the patch would
solve our issue.

Regards,
Bjorn