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USB: remove remaining usages of hcd->state from usbcore and fix regression

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This patch (as1467) removes the last usages of hcd->state from
usbcore.  We no longer check to see if an interrupt handler finds that
a controller has died; instead we rely on host controller drivers to
make an explicit call to usb_hc_died().

This fixes a regression introduced by commit
9b37596a2e (USB: move usbcore away from
hcd->state).  It used to be that when a controller shared an IRQ with
another device and an interrupt arrived while hcd->state was set to
HC_STATE_HALT, the interrupt handler would be skipped.  The commit
removed that test; as a result the current code doesn't skip calling
the handler and ends up believing the controller has died, even though
it's only temporarily stopped.  The solution is to ignore HC_STATE_HALT
following the handler's return.

As a consequence of this change, several of the host controller
drivers need to be modified.  They can no longer implicitly rely on
usbcore realizing that a controller has died because of hcd->state.
The patch adds calls to usb_hc_died() in the appropriate places.

The patch also changes a few of the interrupt handlers.  They don't
expect to be called when hcd->state is equal to HC_STATE_HALT, even if
the controller is still alive.  Early returns were added to avoid any
confusion.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Manuel Lauss <manuel.lauss@googlemail.com>
CC: Rodolfo Giometti <giometti@linux.it>
CC: Olav Kongas <ok@artecdesign.ee>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2011-05-17 17:27:12 -04:00
committed by Greg Kroah-Hartman
parent d23894402b
commit 69fff59de4
6 changed files with 19 additions and 9 deletions
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4
drivers/usb/host/ehci-hcd.c
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@@ -777,8 +777,9 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
goto dead;
}
/* Shared IRQ? */
masked_status = status & INTR_MASK;
if (!masked_status) { /* irq sharing? */
if (!masked_status || unlikely(hcd->state == HC_STATE_HALT)) {
spin_unlock(&ehci->lock);
return IRQ_NONE;
}
@@ -873,6 +874,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
dead:
ehci_reset(ehci);
ehci_writel(ehci, 0, &ehci->regs->configured_flag);
usb_hc_died(hcd);
/* generic layer kills/unlinks all urbs, then
* uses ehci_stop to clean up the rest
*/