Hi, On 02/11/2014 04:00 PM, Roger Quadros wrote: > Hi Hans, > > On 02/11/2014 04:10 PM, Hans de Goede wrote: >> The initial versions of the devicetree enablement patches for ehci-platform >> used "ehci-platform" as compatible string. However this was disliked by various >> reviewers because the platform bus is a Linux invention and devicetree is >> supposed to be OS agnostic. After much discussion I gave up, added a: >> "depends on !PPC_OF" to Kconfig to avoid a known conflict with PPC-OF platforms >> and went with the generic usb-ehci as requested. >> >> In retro-spect I should have stuck to my guns, because the dts files for many >> existing boards already claim to be compatible with "usb-ehci", ie they have: >> >> compatible = "ti,ehci-omap", "usb-ehci"; >> >> In theory this should not be a problem since the "ti,ehci-omap" entry takes >> presedence, but in practice using a conflicting compatible string is an issue, >> because it makes which driver gets used depent on driver registration order. >> >> This patch changes the compatible string claimed by ehci-platform (back) to >> "ehci-platform", avoiding the driver registration / module loading ordering >> problems, and removes the "depends on !PPC_OF" workaround. >> >> Note that there already is a precedent for using ?hci-platform, in the form >> of xhci-platform.c using "xhci-platfrom" as compatible string. >> >> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> >> --- >> Documentation/devicetree/bindings/usb/usb-ehci.txt | 4 ++-- >> drivers/usb/host/Kconfig | 1 - >> drivers/usb/host/ehci-platform.c | 2 +- >> 3 files changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/usb/usb-ehci.txt b/Documentation/devicetree/bindings/usb/usb-ehci.txt >> index 2c1aeeb..46f428a 100644 >> --- a/Documentation/devicetree/bindings/usb/usb-ehci.txt >> +++ b/Documentation/devicetree/bindings/usb/usb-ehci.txt >> @@ -1,7 +1,7 @@ >> USB EHCI controllers >> >> Required properties: >> - - compatible : should be "usb-ehci". >> + - compatible : should be "ehci-platform". > > Won't this break DT binding info for power PC? The powerpc bindings have never been really properly documented, ie they rely on both usb-ehci and ibm,usb-ehci-440epx strings being there, which was never documented. Given the issues surrounding using usb-ehci as a compatible string I think completely removing it from the bindings docs is best. > I'm even OK with removing "usb-ehci" and "usb-ohci" compatibles from all OMAP dts files > since they aren't really compatible with the original PPC driver. I don't think that is necessary, as your grep has shown there are a lot of dts files using compatible = "foo", "usb-?hci"; and some may even have the dts in firmware, so we should simply make sure not to break such dts. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
