From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758150AbYKQHeo (ORCPT ); Mon, 17 Nov 2008 02:34:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755935AbYKQHVm (ORCPT ); Mon, 17 Nov 2008 02:21:42 -0500 Received: from kroah.org ([198.145.64.141]:38707 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755814AbYKQHVj (ORCPT ); Mon, 17 Nov 2008 02:21:39 -0500 Date: Sun, 16 Nov 2008 23:16:58 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alan Stern , David Brownell , Greg Kroah-Hartman Subject: [patch 40/46] USB: EHCI: fix handling of dead controllers Message-ID: <20081117071658.GO29522@kroah.com> References: <20081117070621.430169021@blue.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="usb-ehci-fix-handling-of-dead-controllers.patch" In-Reply-To: <20081117071333.GA29522@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Alan Stern commit 67b2e029743a52670d77864723b4d0d40f7733b5 upstream. This patch (as1165) makes a few small changes in the logic used by ehci-hcd when it encounters a controller error: Instead of printing out the masked status, it prints the original status as read directly from the hardware. It doesn't check for the STS_HALT status bit before taking action. The mere fact that the STS_FATAL bit is set means that something bad has happened and the controller needs to be reset. With the old code this test could never succeed because the STS_HALT bit was masked out from the status. I anticipate that this will prevent the occasional "irq X: nobody cared" problem people encounter when their EHCI controllers die. Signed-off-by: Alan Stern Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -643,7 +643,7 @@ static int ehci_run (struct usb_hcd *hcd static irqreturn_t ehci_irq (struct usb_hcd *hcd) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); - u32 status, pcd_status = 0, cmd; + u32 status, masked_status, pcd_status = 0, cmd; int bh; spin_lock (&ehci->lock); @@ -656,14 +656,14 @@ static irqreturn_t ehci_irq (struct usb_ goto dead; } - status &= INTR_MASK; - if (!status) { /* irq sharing? */ + masked_status = status & INTR_MASK; + if (!masked_status) { /* irq sharing? */ spin_unlock(&ehci->lock); return IRQ_NONE; } /* clear (just) interrupts */ - ehci_writel(ehci, status, &ehci->regs->status); + ehci_writel(ehci, masked_status, &ehci->regs->status); cmd = ehci_readl(ehci, &ehci->regs->command); bh = 0; @@ -731,19 +731,18 @@ static irqreturn_t ehci_irq (struct usb_ /* PCI errors [4.15.2.4] */ if (unlikely ((status & STS_FATAL) != 0)) { + ehci_err(ehci, "fatal error\n"); dbg_cmd (ehci, "fatal", ehci_readl(ehci, &ehci->regs->command)); dbg_status (ehci, "fatal", status); - if (status & STS_HALT) { - ehci_err (ehci, "fatal error\n"); + ehci_halt(ehci); dead: - ehci_reset (ehci); - ehci_writel(ehci, 0, &ehci->regs->configured_flag); - /* generic layer kills/unlinks all urbs, then - * uses ehci_stop to clean up the rest - */ - bh = 1; - } + ehci_reset(ehci); + ehci_writel(ehci, 0, &ehci->regs->configured_flag); + /* generic layer kills/unlinks all urbs, then + * uses ehci_stop to clean up the rest + */ + bh = 1; } if (bh) --