diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2013-01-22 11:37:35 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-27 20:46:28 -0800 |
| commit | 27b2a263fa42cbad0fb33da2de30e4bbc380c43f (patch) | |
| tree | 64d0d743f359aee479fa187b220e8aed4597979b | |
| parent | ef3319d2624e24085982336facc71b414c134f4a (diff) | |
| download | lwn-27b2a263fa42cbad0fb33da2de30e4bbc380c43f.tar.gz lwn-27b2a263fa42cbad0fb33da2de30e4bbc380c43f.zip | |
USB: UHCI: fix IRQ race during initialization
commit 0f815a0a700bc10547449bde6c106051a035a1b9 upstream.
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 <stern@rowland.harvard.edu>
Reported-by: Don Zickus <dzickus@redhat.com>
Tested-by: "Huang, Adrian (ISS Linux TW)" <adrian.huang@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/host/uhci-hcd.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c index fba99b120588..18cd76b779a8 100644 --- a/drivers/usb/host/uhci-hcd.c +++ b/drivers/usb/host/uhci-hcd.c @@ -446,6 +446,10 @@ 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, " @@ -454,7 +458,6 @@ 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, " @@ -472,15 +475,15 @@ 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); } @@ -658,9 +661,9 @@ 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; |