Re: USB Device stops working after 200001 interrupts

[Alan Stern]

On Mon, 3 Feb 2014, Alan Stern wrote:

> On Mon, 3 Feb 2014, Josh Bendavid wrote:
> 
> > Hi Alan,
> > Yes, this hardware was in active use and working fine with 3.5.  The usb/ir
> > issue came up as soon as I moved to 3.13-rc8.  (As I said, this was not the
> > only change strictly speaking, given that I moved from Ubuntu to OpenElec,
> > so there can well be other relevant distro-related changes)
> > 
> > Unfortunately I prefer deep intellectual efforts which don't require much
> > time...

Speaking of which, an idea struck me this morning.  Perhaps this patch 
will make a difference.  (Remove any earlier patches first.)

Without knowing the exact nature of the problem, it's not possible to 
say what will happen.  But it's worth a try.

Alan Stern



Index: usb-3.13/drivers/usb/host/ohci-hcd.c
===================================================================
--- usb-3.13.orig/drivers/usb/host/ohci-hcd.c
+++ usb-3.13/drivers/usb/host/ohci-hcd.c
@@ -801,6 +801,14 @@ static irqreturn_t ohci_irq (struct usb_
                return IRQ_HANDLED;
        }
 
+       /*
+        * Clear all interrupts, enabled or not, except for WDH.
+        * WDH must remain set until after we have read the
+        * ohci->hcca->done_head value, because the controller can
+        * overwrite that value whenever WDH is clear.
+        */
+       ohci_writel(ohci, ints & ~OHCI_INTR_WDH, &regs->intrstatus);
+
        /* We only care about interrupts that are enabled */
        ints &= ohci_readl(ohci, &regs->intrenable);
 

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