Hi Takashi
> Indeed, looks so. In most cases, this doesn't matter since both point
> to the same device object. In some cases like xhci-plat HCD, they
> differ. And sysdev might be a better choice from the consistency
> POV.
>
> But this brought an interesting question, too. eg. USB chipidea
> HCD uses platform devices for both controller and sysdev, and I
> couldn't find any DMA mask setup. So, no matter what to use, the uwc
> driver would be broken on this... Maybe it's just not covered.
Did you do a git bisect to see what actually broke it? "1161db6776bd:
media: usb: pwc: Don't use coherent DMA buffers for ISO transfer"
introduced the code, not the regression. If we understand the
regression, that might give us the answer about chipidea.
Andrew
