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
