On Thursday 21 February 2008, Alan Stern wrote: > > ========= CUT HERE > > Modify EHCI irq handling on the theory that at least some of the > > "lost" IRQs are caused by goofage between multiple lowlevel IRQ > > acking mechanisms: try rescanning before we exit the handler, in > > case the EHCI-internal ack (by clearing the irq status) doesn't > > always suffice for IRQs triggered nearly back-to-back. > > > > --- > > drivers/usb/host/ehci-hcd.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > --- g26.orig/drivers/usb/host/ehci-hcd.c 2008-02-20 13:26:00.000000000 > > -0800 > > +++ g26/drivers/usb/host/ehci-hcd.c 2008-02-20 13:54:37.000000000 -0800 > > @@ -638,6 +638,8 @@ static irqreturn_t ehci_irq (struct usb_ > > return IRQ_NONE; > > } > > > > +retrigger: > > + > > /* clear (just) interrupts */ > > ehci_writel(ehci, status, &ehci->regs->status); > > cmd = ehci_readl(ehci, &ehci->regs->command); > > @@ -725,6 +727,12 @@ dead: > > > > if (bh) > > ehci_work (ehci); > > + > > + status = ehci_readl(ehci, &ehci->regs->status); > > + status &= INTR_MASK; > > + if (status) > > + goto retrigger; > > + > > spin_unlock (&ehci->lock); > > if (pcd_status & STS_PCD) > > usb_hcd_poll_rh_status(hcd); > > There's one little problem here. As a result of this change, the line > where pcd_status gets set (not shown in this patch) needs to be changed > to: > > pcd_status |= (status & STS_PCD);
Actually, no change is needed. It's initialized to zero, then set to "status" given "if (status & STS_PCD)", and never cleared. So if it's ever set, it stays set... > > Then the test shown above can be simplified to: > > if (pcd_status) True with the current code too ... -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
