From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941214AbcIHKRh (ORCPT ); Thu, 8 Sep 2016 06:17:37 -0400 Received: from mout.kundenserver.de ([212.227.17.24]:54596 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758838AbcIHKRg (ORCPT ); Thu, 8 Sep 2016 06:17:36 -0400 From: Arnd Bergmann To: Felipe Balbi Cc: Peter Chen , Leo Li , Grygorii Strashko , Russell King - ARM Linux , Catalin Marinas , Yoshihiro Shimoda , "linux-usb@vger.kernel.org" , Sekhar Nori , lkml , Stuart Yoder , Scott Wood , David Fisher , "Thang Q. Nguyen" , Alan Stern , Greg Kroah-Hartman , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Date: Thu, 08 Sep 2016 12:17:21 +0200 Message-ID: <4934737.egJZVdaLZs@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-34-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <87lgz2iv6d.fsf@linux.intel.com> References: <2733202.7lpFC7RnDm@wuerfel> <87lgz2iv6d.fsf@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:3jE/cDBy6r+nsZoD7fmJVLBHbdO6JTacixBviKRA3LUkuo7wiad ror8zAmMy/k+IsdxS3u1nL7YRAGeZisNcTpEDpGhKO54jHMpg4F/OvWHH6WOzk11vHg/0X/ vIcqYQVegTr/NKnrLVcbuQWlXk66dsxCwubexHUznlQb31ZV0EfEWL8hD9HIu5sokbTahlR Z7X/RoxN887+qZ62qwvdw== X-UI-Out-Filterresults: notjunk:1;V01:K0:WxecayFh4Gs=:CwXeANN5LuJJ4suhta9Lq1 XCb+7zkhpKqBL08YSa3umzlq88gYTkf5snO1KOaFIDrdUptA9Y8wR0Owc4cr2D/hXpRC1Q+rq xy4YQzw84jOKc27sKDhan6aIsz1KpPmh3+fxaEZZ3H7CKAdDfThLpW4CSTldhZYn894FJGY2v vft+xqHIJ3PBN0kM/tvHc6hBGuw7lHoEJpzMd3lim2qe63Yvqtp3Md/CbGN+/2xss6XRU5hbr EncX7AuQ7tdgsw1hG2txm7zsqcs3YlQcR/47PzsNODgg6cE9QnnlO2LBj+m20f8NRextkr+Tp N2e9XI8qGBQFHCS1cD1lKwAXsHg1vx65PWHXM5MfYsmKr4MckXyN/ipMsmnPabgsir2ixfGm0 JRiv8g8JXpRtWYAUD42YZUAy7ls6Nz+9ktVC1X8aQYEWCAcJNQ8cqgdQtP7ZOwuRLmuwGTU5v o8pnuG1mUtKkTOtiCc4c8g2dvon+CQ8N4lKToVGZ9PhsJVrp1inpW5n6MfcxFd/9X5cHUKAfs 9Q7bMNXBnF1Kx+p+ZklTQcttnCg4ckULlg4KwVYznxp+UZiQSiomHed/G/I0JgMGtOWYzd0Wm Alfi1rVM8RerLGUH6f1AplbrgtFL9n+lKUabGa4mlSb06Zh1Kh1KYYUofh2nFt7dCuZ/M5Jy7 FsQ+PrcB1dmmMHwxeeBF6Zu57/SV1dXv++P7RolLb0Rw3VZ0KgbUEHOMlrTWtB2VqYpykAms6 tlYGHCZC8XA5UZqI Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, September 8, 2016 12:43:06 PM CEST Felipe Balbi wrote: > 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. But there is often a parent device in DT, as the xhci device is attached to some internal bus that gets turned into a platform_device as well, so checking whether there is a parent will get the wrong device node. > > 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? That would be incompatible with the USB binding, as the sysdev is assumed to be a USB host controller with #address-cells=<1> and #size-cells=<0> in order to hold the child devices, for example: / { omap_dwc3_1: omap_dwc3_1@48880000 { compatible = "ti,dwc3"; #address-cells = <1>; #size-cells = <1>; ranges; usb1: usb@48890000 { compatible = "snps,dwc3"; reg = <0x48890000 0x17000>; #address-cells = <1>; #size-cells = <0>; interrupts = , , ; interrupt-names = "peripheral", "host", "otg"; phys = <&usb2_phy1>, <&usb3_phy1>; phy-names = "usb2-phy", "usb3-phy"; hub@1 { compatible = "usb5e3,608"; reg = <1>; #address-cells = <1>; #size-cells = <0>; ethernet@1 { compatible = "usb424,ec00"; mac-address = [00 11 22 33 44 55]; reg = <1>; }; }; }; }; It's also the node that contains the "phys" properties and presumably other properties like "otg-rev", "maximum-speed" etc. If we make the sysdev point to the parent, then we can no longer look up those properties and child devices from the USB core code by looking at "sysdev->of_node". Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Thu, 08 Sep 2016 12:17:21 +0200 Subject: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev In-Reply-To: <87lgz2iv6d.fsf@linux.intel.com> References: <2733202.7lpFC7RnDm@wuerfel> <87lgz2iv6d.fsf@linux.intel.com> Message-ID: <4934737.egJZVdaLZs@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday, September 8, 2016 12:43:06 PM CEST Felipe Balbi wrote: > 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. But there is often a parent device in DT, as the xhci device is attached to some internal bus that gets turned into a platform_device as well, so checking whether there is a parent will get the wrong device node. > > 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? That would be incompatible with the USB binding, as the sysdev is assumed to be a USB host controller with #address-cells=<1> and #size-cells=<0> in order to hold the child devices, for example: / { omap_dwc3_1: omap_dwc3_1 at 48880000 { compatible = "ti,dwc3"; #address-cells = <1>; #size-cells = <1>; ranges; usb1: usb at 48890000 { compatible = "snps,dwc3"; reg = <0x48890000 0x17000>; #address-cells = <1>; #size-cells = <0>; interrupts = , , ; interrupt-names = "peripheral", "host", "otg"; phys = <&usb2_phy1>, <&usb3_phy1>; phy-names = "usb2-phy", "usb3-phy"; hub at 1 { compatible = "usb5e3,608"; reg = <1>; #address-cells = <1>; #size-cells = <0>; ethernet at 1 { compatible = "usb424,ec00"; mac-address = [00 11 22 33 44 55]; reg = <1>; }; }; }; }; It's also the node that contains the "phys" properties and presumably other properties like "otg-rev", "maximum-speed" etc. If we make the sysdev point to the parent, then we can no longer look up those properties and child devices from the USB core code by looking at "sysdev->of_node". Arnd