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uio: uio_pci_generic: Remove useless spin_lock 

The spin_lock in uio_pci_generic.c is only used in the interrupt
handler, which cannot be executed twice at the same time.
That makes the lock rather pointless. This patch removes it.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Chris Wright <chrisw@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Anthony Foiani <anthony.foiani@gmail.com>
Reported-by: Anthony Foiani <anthony.foiani@gmail.com>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Hans J. Koch <hjk@hansjkoch.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Hans J. Koch 2011-08-09 20:53:41 +02:00 committed by Greg Kroah-Hartman
parent a406f75840
commit 4e0b72fd74
1 changed files with 0 additions and 5 deletions
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5
drivers/uio/uio_pci_generic.c
View File

@ -24,7 +24,6 @@
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/uio_driver.h>
#include <linux/spinlock.h>
#define DRIVER_VERSION "0.01.0"
#define DRIVER_AUTHOR "Michael S. Tsirkin <mst@redhat.com>"
@ -33,7 +32,6 @@
struct uio_pci_generic_dev {
struct uio_info info;
struct pci_dev *pdev;
spinlock_t lock; /* guards command register accesses */
};
static inline struct uio_pci_generic_dev *
@ -57,7 +55,6 @@ static irqreturn_t irqhandler(int irq, struct uio_info *info)
BUILD_BUG_ON(PCI_COMMAND % 4);
BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS);
spin_lock_irq(&gdev->lock);
pci_block_user_cfg_access(pdev);
/* Read both command and status registers in a single 32-bit operation.
@ -83,7 +80,6 @@ static irqreturn_t irqhandler(int irq, struct uio_info *info)
done:
pci_unblock_user_cfg_access(pdev);
spin_unlock_irq(&gdev->lock);
return ret;
}
@ -158,7 +154,6 @@ static int __devinit probe(struct pci_dev *pdev,
gdev->info.irq_flags = IRQF_SHARED;
gdev->info.handler = irqhandler;
gdev->pdev = pdev;
spin_lock_init(&gdev->lock);
if (uio_register_device(&pdev->dev, &gdev->info))
goto err_register;