[05/12] usb: usblp: use irqsave() in USB's complete callback
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2018-06-24 22:08:38
Subsystem:
the rest, usb printer driver (usblp), usb subsystem · Maintainers:
Linus Torvalds, Pete Zaitcev, Greg Kroah-Hartman
The USB completion callback does not disable interrupts while acquiring the lock. We want to remove the local_irq_disable() invocation from __usb_hcd_giveback_urb() and therefore it is required for the callback handler to disable the interrupts while acquiring the lock. The callback may be invoked either in IRQ or BH context depending on the USB host controller. Use the _irqsave() variant of the locking primitives. Cc: Pete Zaitcev <zaitcev@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- drivers/usb/class/usblp.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index d058d7a31e7c..407a7a6198a2 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c@@ -292,6 +292,7 @@ static void usblp_bulk_read(struct urb *urb) { struct usblp *usblp = urb->context; int status = urb->status; + unsigned long flags; if (usblp->present && usblp->used) { if (status)
@@ -299,14 +300,14 @@ static void usblp_bulk_read(struct urb *urb) "nonzero read bulk status received: %d\n", usblp->minor, status); } - spin_lock(&usblp->lock); + spin_lock_irqsave(&usblp->lock, flags); if (status < 0) usblp->rstatus = status; else usblp->rstatus = urb->actual_length; usblp->rcomplete = 1; wake_up(&usblp->rwait); - spin_unlock(&usblp->lock); + spin_unlock_irqrestore(&usblp->lock, flags); usb_free_urb(urb); }
@@ -315,6 +316,7 @@ static void usblp_bulk_write(struct urb *urb) { struct usblp *usblp = urb->context; int status = urb->status; + unsigned long flags; if (usblp->present && usblp->used) { if (status)
@@ -322,7 +324,7 @@ static void usblp_bulk_write(struct urb *urb) "nonzero write bulk status received: %d\n", usblp->minor, status); } - spin_lock(&usblp->lock); + spin_lock_irqsave(&usblp->lock, flags); if (status < 0) usblp->wstatus = status; else
@@ -330,7 +332,7 @@ static void usblp_bulk_write(struct urb *urb) usblp->no_paper = 0; usblp->wcomplete = 1; wake_up(&usblp->wwait); - spin_unlock(&usblp->lock); + spin_unlock_irqrestore(&usblp->lock, flags); usb_free_urb(urb); }