From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@kernel.org (Felipe Balbi) Date: Thu, 08 Sep 2016 12:43:06 +0300 Subject: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev In-Reply-To: <2733202.7lpFC7RnDm@wuerfel> References: <6739240.VDAnDBppH0@wuerfel> <87y432iylr.fsf@linux.intel.com> <2733202.7lpFC7RnDm@wuerfel> Message-ID: <87lgz2iv6d.fsf@linux.intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Arnd Bergmann writes: > On Thursday, September 8, 2016 11:29:04 AM CEST Felipe Balbi wrote: >> > If we do that, we have to put child devices of the dwc3 devices into >> > the platform glue, and it also breaks those dwc3 devices that don't >> > have a parent driver. >> >> Well, this is easy to fix: >> >> if (dwc->dev->parent) { >> dwc->sysdev = dwc->dev->parent; >> } else { >> dev_info(dwc->dev, "Please provide a glue layer!\n"); >> dwc->sysdev = dwc->dev; >> } > > I don't understand. Do you mean we should have an extra level of > stacking and splitting "static struct platform_driver dwc3_driver" > in two so instead of > > "qcom,dwc3" -> "snps,dwc3" (usb_bus.sysdev) -> "xhci" (usb_bus.dev) > > we do this? > > "qcom,dwc3" -> "snps,dwc3" (usb_bus.sysdev) -> "dwc3-glue" -> "xhci" (usb_bus.dev) no :-) If we have a parent device, use that as sysdev, otherwise use self as sysdev. > That sounds a bit clumsy for the sake of consistency with PCI. > The advantage is that xhci can always use the grandparent device > as sysdev whenever it isn't probed through PCI or firmware > itself, but the purpose of the dwc3-glue is otherwise questionable. > > How about adding a 'compatible="snps,dwc3-pci"' property for the dwc3 > device when that is created from the PCI driver and checking for that > with the device property interface instead? If it's "snps,dwc3" > we use the device itself while for "snps,dwc3-pci", we use the parent? Any reason why we wouldn't use e.g. dwc3-omap.dev as sysdev? -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 800 bytes Desc: not available URL: