Commit 0f815a0a authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: UHCI: fix IRQ race during initialization



This patch (as1644) fixes a race that occurs during startup in
uhci-hcd.  If the IRQ line is shared with other devices, it's possible
for the handler routine to be called before the data structures are
fully initialized.

The problem is fixed by adding a check to the IRQ handler routine.  If
the initialization hasn't finished yet, the routine will return
immediately.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reported-by: default avatarDon Zickus <dzickus@redhat.com>
Tested-by: default avatar"Huang, Adrian (ISS Linux TW)" <adrian.huang@hp.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ad2e6329
...@@ -447,6 +447,10 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd) ...@@ -447,6 +447,10 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
return IRQ_NONE; return IRQ_NONE;
uhci_writew(uhci, status, USBSTS); /* Clear it */ uhci_writew(uhci, status, USBSTS); /* Clear it */
spin_lock(&uhci->lock);
if (unlikely(!uhci->is_initialized)) /* not yet configured */
goto done;
if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) { if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
if (status & USBSTS_HSE) if (status & USBSTS_HSE)
dev_err(uhci_dev(uhci), "host system error, " dev_err(uhci_dev(uhci), "host system error, "
...@@ -455,7 +459,6 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd) ...@@ -455,7 +459,6 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
dev_err(uhci_dev(uhci), "host controller process " dev_err(uhci_dev(uhci), "host controller process "
"error, something bad happened!\n"); "error, something bad happened!\n");
if (status & USBSTS_HCH) { if (status & USBSTS_HCH) {
spin_lock(&uhci->lock);
if (uhci->rh_state >= UHCI_RH_RUNNING) { if (uhci->rh_state >= UHCI_RH_RUNNING) {
dev_err(uhci_dev(uhci), dev_err(uhci_dev(uhci),
"host controller halted, " "host controller halted, "
...@@ -473,15 +476,15 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd) ...@@ -473,15 +476,15 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
* pending unlinks */ * pending unlinks */
mod_timer(&hcd->rh_timer, jiffies); mod_timer(&hcd->rh_timer, jiffies);
} }
spin_unlock(&uhci->lock);
} }
} }
if (status & USBSTS_RD) if (status & USBSTS_RD) {
spin_unlock(&uhci->lock);
usb_hcd_poll_rh_status(hcd); usb_hcd_poll_rh_status(hcd);
else { } else {
spin_lock(&uhci->lock);
uhci_scan_schedule(uhci); uhci_scan_schedule(uhci);
done:
spin_unlock(&uhci->lock); spin_unlock(&uhci->lock);
} }
...@@ -662,9 +665,9 @@ static int uhci_start(struct usb_hcd *hcd) ...@@ -662,9 +665,9 @@ static int uhci_start(struct usb_hcd *hcd)
*/ */
mb(); mb();
spin_lock_irq(&uhci->lock);
configure_hc(uhci); configure_hc(uhci);
uhci->is_initialized = 1; uhci->is_initialized = 1;
spin_lock_irq(&uhci->lock);
start_rh(uhci); start_rh(uhci);
spin_unlock_irq(&uhci->lock); spin_unlock_irq(&uhci->lock);
return 0; return 0;
......
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