From: Hans J. Koch Date: Tue, 9 Aug 2011 18:53:41 +0000 (+0200) Subject: uio: uio_pci_generic: Remove useless spin_lock X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4e0b72fd7444e07e2870d193ce8fb6b0b00f5a89;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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" Cc: Chris Wright Cc: Jesse Barnes Cc: Sebastian Andrzej Siewior Cc: Anthony Foiani Reported-by: Anthony Foiani Reported-by: Sebastian Andrzej Siewior Signed-off-by: Hans J. Koch Acked-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- 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 #include #include -#include #define DRIVER_VERSION "0.01.0" #define DRIVER_AUTHOR "Michael S. Tsirkin " @@ -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;