> On Fri, Aug 16, 2013 at 02:22:43AM +0000, Wang, Yu Y wrote: > > > On Thu, Aug 15, 2013 at 06:43:59PM -0700, Sarah Sharp wrote: > > > > The xHCI platform driver calls into usb_add_hcd to register the > > > > irq for its platform device. It does not want the xHCI generic > > > > driver to register an interrupt for it at all. The original code > > > > did that by setting the XHCI_BROKEN_MSI quirk, which tells the > > > > xHCI driver to not enable MSI or MSI-X for a PCI host. > > > > > > > > Unfortunately, if CONFIG_PCI is enabled, and CONFIG_USB_DW3 is > > > > enabled, the xHCI generic driver will attempt to register a legacy > > > > PCI interrupt for the xHCI platform device in > > > > xhci_try_enable_msi(). This will result in a bogus irq being > > > > registered, since the underlying device is a platform_device, not > > > > a pci_device, and thus the pci_device->irq pointer will be bogus. > > > > > > What shipping hardware has this problem today? > > > > > > In other words, doesn't seem like late -rc material to me. > > > > > > thanks, > > > > > > greg k-h > > > > [Yu:] I met this issue on Intel mobile SOC(Merrifield). But to my > > understanding, this issue should not depend on hardware. This is one > software issue. > > > > When system enabled CONFIG_PCI and xHCI driver registered as platform > > device driver. Then xHCI-plat driver will be met initialization failed. > > Yes, but what "normal" system ever registers the xHCI driver as a platform > driver? Does this happen today with systems? Which ones? [Yu:] Yes. I think there is no scenario for xHCI driver register as a platform driver. Then can't reproduce on normal system. > > And is Merrifield shipping in devices today (sorry, I don't know the Intel mobile > codenames anymore, it's been almost a year since I saw my last Intel > powerpoint presentation... > [Yu:] It should not only on Merrifield. But should be also met for ARM SOC which use dwc3 controller as xHCI controller. Because DWC3 driver register xHCI as platform driver by default. So this issue can be reproduce. > thanks, > > greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
