From 6a29beef9d1b16c762e469d77e28c3de3f5c3dbb Mon Sep 17 00:00:00 2001 From: Peter Chen Date: Wed, 17 May 2017 18:32:02 +0300 Subject: usb: host: xhci-ring: don't need to clear interrupt pending for MSI enabled hcd According to xHCI spec Figure 30: Interrupt Throttle Flow Diagram If PCI Message Signaled Interrupts (MSI or MSI-X) are enabled, then the assertion of the Interrupt Pending (IP) flag in Figure 30 generates a PCI Dword write. The IP flag is automatically cleared by the completion of the PCI write. the MSI enabled HCs don't need to clear interrupt pending bit, but hcd->irq = 0 doesn't equal to MSI enabled HCD. At some Dual-role controller software designs, it sets hcd->irq as 0 to avoid HCD requesting interrupt, and they want to decide when to call usb_hcd_irq by software. Signed-off-by: Peter Chen Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- include/linux/usb/hcd.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index a469999a106d..50398b69ca44 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -148,6 +148,7 @@ struct usb_hcd { unsigned rh_registered:1;/* is root hub registered? */ unsigned rh_pollable:1; /* may we poll the root hub? */ unsigned msix_enabled:1; /* driver has MSI-X enabled? */ + unsigned msi_enabled:1; /* driver has MSI enabled? */ unsigned remove_phy:1; /* auto-remove USB phy */ /* The next flag is a stopgap, to be removed when all the HCDs -- cgit v1.2.3-59-g8ed1b