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authorHans J. Koch <hjk@hansjkoch.de>2011-08-09 20:53:41 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-22 17:52:00 -0700
commit4e0b72fd7444e07e2870d193ce8fb6b0b00f5a89 (patch)
treed81946567cef8109de9e95e64bee846f5986f13d /drivers/uio
parenta406f75840e15afbabd98cb64ae36b51424a8033 (diff)
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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>
Diffstat (limited to 'drivers/uio')
-rw-r--r--drivers/uio/uio_pci_generic.c5
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/uio/uio_pci_generic.c b/drivers/uio/uio_pci_generic.c
index fc22e1e6f215..02bd47bdee1c 100644
--- a/drivers/uio/uio_pci_generic.c
+++ b/drivers/uio/uio_pci_generic.c
@@ -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;