This is a note to let you know that I've just added the patch titled
USB: UHCI: fix IRQ race during initialization
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 0f815a0a700bc10547449bde6c106051a035a1b9 Mon Sep 17 00:00:00 2001
From: Alan Stern <[email protected]>
Date: Tue, 22 Jan 2013 11:37:35 -0500
Subject: 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: Alan Stern <[email protected]>
Reported-by: Don Zickus <[email protected]>
Tested-by: "Huang, Adrian (ISS Linux TW)" <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/host/uhci-hcd.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 4b9e9ab..4f64d24 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -447,6 +447,10 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
return IRQ_NONE;
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_HSE)
dev_err(uhci_dev(uhci), "host system error, "
@@ -455,7 +459,6 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
dev_err(uhci_dev(uhci), "host controller process "
"error, something bad happened!\n");
if (status & USBSTS_HCH) {
- spin_lock(&uhci->lock);
if (uhci->rh_state >= UHCI_RH_RUNNING) {
dev_err(uhci_dev(uhci),
"host controller halted, "
@@ -473,15 +476,15 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd)
* pending unlinks */
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);
- else {
- spin_lock(&uhci->lock);
+ } else {
uhci_scan_schedule(uhci);
+ done:
spin_unlock(&uhci->lock);
}
@@ -662,9 +665,9 @@ static int uhci_start(struct usb_hcd *hcd)
*/
mb();
+ spin_lock_irq(&uhci->lock);
configure_hc(uhci);
uhci->is_initialized = 1;
- spin_lock_irq(&uhci->lock);
start_rh(uhci);
spin_unlock_irq(&uhci->lock);
return 0;
--
1.8.1.rc1.5.g7e0651a
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