Messages in this thread Patch in this message | | | Subject | Re: [PATCH] USB and Driver Core patches for 2.6.10 | Date | Fri, 7 Jan 2005 21:47:38 -0800 | From | Greg KH <> |
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ChangeSet 1.1938.439.56, 2005/01/07 10:29:46-08:00, david-b@pacbell.net
[PATCH] USB: ehci "hc died" on startup (chip bug workaround)
This fixes OSDL bugid #3056 for at least some users, where the EHCI driver gets a "fatal error" IRQ on startup ... only on certain boards, starting with the 2.6.6 or 2.6.7 kernels. These IRQs normally indicate that an invalid DMA address got passed to the controller, or something equally nasty and unrecoverable.
But it turns out that some of these controllers (at least ALI and Intel) are lying. They're issuing these IRQs without stopping, contrary to the EHCI spec ... so these IRQs can be recovered from. Thanks to Christian Iversen for noticing that his ALI controller would continue operating, which was the first real break in this annoying case.
This patch tests for these bogus IRQs, and ignores them ... working around what's clearly a chip bug. It's not clear why we started triggering that bug, but at least EHCI is now usable on boards exhibiting this problem.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
drivers/usb/host/ehci-hcd.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-)
diff -Nru a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c --- a/drivers/usb/host/ehci-hcd.c 2005-01-07 15:34:45 -08:00 +++ b/drivers/usb/host/ehci-hcd.c 2005-01-07 15:34:45 -08:00 @@ -883,13 +883,20 @@ /* PCI errors [4.15.2.4] */ if (unlikely ((status & STS_FATAL) != 0)) { - ehci_err (ehci, "fatal error\n"); + /* bogus "fatal" IRQs appear on some chips... why? */ + status = readl (&ehci->regs->status); + dbg_cmd (ehci, "fatal", readl (&ehci->regs->command)); + dbg_status (ehci, "fatal", status); + if (status & STS_HALT) { + ehci_err (ehci, "fatal error\n"); dead: - ehci_reset (ehci); - /* generic layer kills/unlinks all urbs, then - * uses ehci_stop to clean up the rest - */ - bh = 1; + ehci_reset (ehci); + writel (0, &ehci->regs->configured_flag); + /* generic layer kills/unlinks all urbs, then + * uses ehci_stop to clean up the rest + */ + bh = 1; + } } if (bh) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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