Messages in this thread |  | | | Date | Fri, 17 Feb 2012 11:15:45 +0100 | | From | Clemens Ladisch <> | | Subject | Re: [PATCH] usb: enable pci MSI/MSIX in usb core |
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Alex,Shi wrote: >> The controller driver will need to know which of the multiple MSI-X >> interrupts has been raised: >> >> irqreturn_t (*msix_irq)(struct usb_hcd *hcd, unsigned int nr_or_index); > > Actually, hcd has 2 object for msix, msix_count and msix_entries. > > Do you mean msix_count maybe smaller than we decide in hcd_setup_msix()?
No. But when msic_count > 1, we have multiple interrupts. > Which situation will make this?
Assume that an XHCI controller has two rings, and that each one gets its own MSI-X interrupt. How should the driver decide which of the rings needs to be handled?
irqreturn_t xhci_msix_irq(struct usb_hcd *hcd) { struct xhci_hcd *xhci = hcd_to_xhci(hcd); if (...) handle(xhci->ring[0]); else handle(xhci->ring[1]); } I.e., what should go into the if()?
Regards, Clemens
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