[PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt

[PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt

[Benjamin Herrenschmidt]

The OHCI driver's IRQ handler, while processing a WDH interrupt, masks
and unmasks it. I believe this is both broken (no dealign with write
posting) and totally useless as the IRQ cannot re-occur while we are in
the handler anyway. 
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

It might be a leftover related to the bogus optmisation that I've removed
in a separate patch. Anyway, I don't think it's any use so let's remove
to useless MMIO writes.

 drivers/usb/host/ohci-hcd.c |    4 ----
 1 file changed, 4 deletions(-)

Index: linux-work/drivers/usb/host/ohci-hcd.c
===================================================================
--- linux-work.orig/drivers/usb/host/ohci-hcd.c	2007-11-26 09:17:52.000000000 +1100
+++ linux-work/drivers/usb/host/ohci-hcd.c	2007-11-26 09:17:58.000000000 +1100
@@ -807,13 +807,9 @@ static irqreturn_t ohci_irq (struct usb_
 	}
 
 	if (ints & OHCI_INTR_WDH) {
-		if (HC_IS_RUNNING(hcd->state))
-			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrdisable);
 		spin_lock (&ohci->lock);
 		dl_done_list (ohci);
 		spin_unlock (&ohci->lock);
-		if (HC_IS_RUNNING(hcd->state))
-			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrenable);
 	}
 
 	if (quirk_zfmicro(ohci) && (ints & OHCI_INTR_SF)) {

Re: [PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt

[David Brownell]

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: [PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt

The OHCI driver's IRQ handler, while processing a WDH interrupt, masks
and unmasks it.  I believe this is both broken (the write may still be
posted during the donelist processing it's trying to safeguard) and
useless as this IRQ may not be reissued until it's acked (unless this
legacy code is an uncommented workaround for some chip erratum).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
Worth IMO holding till 2.6.25-early.

--- g26.orig/drivers/usb/host/ohci-hcd.c	2007-12-06 08:42:24.000000000 -0800
+++ g26/drivers/usb/host/ohci-hcd.c	2007-12-06 08:42:29.000000000 -0800
@@ -807,13 +807,9 @@ static irqreturn_t ohci_irq (struct usb_
 	}
 
 	if (ints & OHCI_INTR_WDH) {
-		if (HC_IS_RUNNING(hcd->state))
-			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrdisable);
 		spin_lock (&ohci->lock);
 		dl_done_list (ohci);
 		spin_unlock (&ohci->lock);
-		if (HC_IS_RUNNING(hcd->state))
-			ohci_writel (ohci, OHCI_INTR_WDH, &regs->intrenable);
 	}
 
 	if (quirk_zfmicro(ohci) && (ints & OHCI_INTR_SF)) {