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From: David Brownell <david-b@pacbell.net>
To: Greg KH <greg@kroah.com>
Cc: linux-usb-devel@lists.sourceforge.net, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt
Date: Thu, 6 Dec 2007 13:29:46 -0800	[thread overview]
Message-ID: <200712061329.47591.david-b@pacbell.net> (raw)
In-Reply-To: <20071125225543.374E0DDF17@ozlabs.org>

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)) {

      reply	other threads:[~2007-12-06 21:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-25 22:54 [PATCH 2/2] usb: Remove OHCI useless masking/unmasking of WDH interrupt Benjamin Herrenschmidt
2007-12-06 21:29 ` David Brownell [this message]

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