When some xHCI host controllers fall back to use the legacy IRQ,
the member irq_descr of the usb_hcd structure will be empty. This
leads to the empty string of the xHCI host controller in
/proc/interrupts. Here is the example (The irq 19 is the xHCI host
controller):
CPU0
0: 91 IO-APIC-edge timer
8: 1 IO-APIC-edge rtc0
9: 7191 IO-APIC-fasteoi acpi
18: 104 IR-IO-APIC-fasteoi ehci_hcd:usb1, ehci_hcd:usb2
19: 473 IR-IO-APIC-fasteoi
After applying the patch, the name of the registered xHCI host
controller can be displayed correctly. Here is the example:
CPU0
0: 91 IO-APIC-edge timer
8: 1 IO-APIC-edge rtc0
9: 7191 IO-APIC-fasteoi acpi
18: 104 IR-IO-APIC-fasteoi ehci_hcd:usb1, ehci_hcd:usb2
19: 473 IR-IO-APIC-fasteoi xhci_hcd:usb3
Tested on v3.14-rc4.
Signed-off-by: Adrian Huang <ahuan...@lenovo.com>
Reviewed-by: Nagananda Chumbalkar <nchumbal...@lenovo.com>
---
drivers/usb/host/xhci.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6fe577d..e8e8dae 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -390,6 +390,10 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
}
legacy_irq:
+ if (!strlen(hcd->irq_descr))
+ snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
+ hcd->driver->description, hcd->self.busnum);
+
/* fall back to legacy interrupt*/
ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
hcd->irq_descr, hcd);
--
1.8.1.2
