From 31adcb0a9cba3b7e3560c6364aaa8d0060764e12 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 25 Jun 2018 00:08:36 +0200 Subject: [PATCH] usb: core: use irqsave() in sg_complete() complete callback 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. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 1a15392326fc..228672f2c4a1 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -269,10 +269,11 @@ static void sg_clean(struct usb_sg_request *io) static void sg_complete(struct urb *urb) { + unsigned long flags; struct usb_sg_request *io = urb->context; int status = urb->status; - spin_lock(&io->lock); + spin_lock_irqsave(&io->lock, flags); /* In 2.5 we require hcds' endpoint queues not to progress after fault * reports, until the completion callback (this!) returns. That lets @@ -306,7 +307,7 @@ static void sg_complete(struct urb *urb) * unlink pending urbs so they won't rx/tx bad data. * careful: unlink can sometimes be synchronous... */ - spin_unlock(&io->lock); + spin_unlock_irqrestore(&io->lock, flags); for (i = 0, found = 0; i < io->entries; i++) { if (!io->urbs[i]) continue; @@ -323,7 +324,7 @@ static void sg_complete(struct urb *urb) } else if (urb == io->urbs[i]) found = 1; } - spin_lock(&io->lock); + spin_lock_irqsave(&io->lock, flags); } /* on the last completion, signal usb_sg_wait() */ @@ -332,7 +333,7 @@ static void sg_complete(struct urb *urb) if (!io->count) complete(&io->complete); - spin_unlock(&io->lock); + spin_unlock_irqrestore(&io->lock, flags); }