diff mbox

SOLO6x10: remove unneeded register locking and barriers.

Message ID m3twuiwc3j.fsf@t19.piap.pl (mailing list archive)
State New, archived
Headers show

Commit Message

Krzysztof Hałasa June 8, 2015, 1:42 p.m. UTC 
readl() and writel() are atomic, we don't need the spin lock.
Also, flushing posted write buffer isn't required. Especially on read :-)

Signed-off-by: Krzysztof Ha?asa <khalasa@piap.pl>

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Comments

Ismael Luceno June 14, 2015, 9:53 p.m. UTC | #1 
On Mon, 08 Jun 2015 15:42:24 +0200
khalasa@piap.pl (Krzysztof Ha?asa) wrote:
> readl() and writel() are atomic, we don't need the spin lock.
> Also, flushing posted write buffer isn't required. Especially on
> read :-)
> 
> Signed-off-by: Krzysztof Ha?asa <khalasa@piap.pl>
> 
> --- a/drivers/media/pci/solo6x10/solo6x10-core.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-core.c
> @@ -483,7 +483,6 @@ static int solo_pci_probe(struct pci_dev *pdev,
> const struct pci_device_id *id) 
>  	solo_dev->type = id->driver_data;
>  	solo_dev->pdev = pdev;
> -	spin_lock_init(&solo_dev->reg_io_lock);
>  	ret = v4l2_device_register(&pdev->dev, &solo_dev->v4l2_dev);
>  	if (ret)
>  		goto fail_probe;
> --- a/drivers/media/pci/solo6x10/solo6x10.h
> +++ b/drivers/media/pci/solo6x10/solo6x10.h
> @@ -201,7 +201,6 @@ struct solo_dev {
>  	int			nr_ext;
>  	u32			irq_mask;
>  	u32			motion_mask;
> -	spinlock_t		reg_io_lock;
>  	struct v4l2_device	v4l2_dev;
>  
>  	/* tw28xx accounting */
> @@ -283,36 +282,13 @@ struct solo_dev {
>  
>  static inline u32 solo_reg_read(struct solo_dev *solo_dev, int reg)
>  {
> -	unsigned long flags;
> -	u32 ret;
> -	u16 val;
> -
> -	spin_lock_irqsave(&solo_dev->reg_io_lock, flags);
> -
> -	ret = readl(solo_dev->reg_base + reg);
> -	rmb();
> -	pci_read_config_word(solo_dev->pdev, PCI_STATUS, &val);
> -	rmb();
> -
> -	spin_unlock_irqrestore(&solo_dev->reg_io_lock, flags);
> -
> -	return ret;
> +	return readl(solo_dev->reg_base + reg);
>  }
>  
>  static inline void solo_reg_write(struct solo_dev *solo_dev, int reg,
>  				  u32 data)
>  {
> -	unsigned long flags;
> -	u16 val;
> -
> -	spin_lock_irqsave(&solo_dev->reg_io_lock, flags);
> -
>  	writel(data, solo_dev->reg_base + reg);
> -	wmb();
> -	pci_read_config_word(solo_dev->pdev, PCI_STATUS, &val);
> -	rmb();
> -
> -	spin_unlock_irqrestore(&solo_dev->reg_io_lock, flags);
>  }
>  
>  static inline void solo_irq_on(struct solo_dev *dev, u32 mask)

Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
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diff mbox

Patch

--- a/drivers/media/pci/solo6x10/solo6x10-core.c
+++ b/drivers/media/pci/solo6x10/solo6x10-core.c
@@ -483,7 +483,6 @@  static int solo_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	solo_dev->type = id->driver_data;
 	solo_dev->pdev = pdev;
-	spin_lock_init(&solo_dev->reg_io_lock);
 	ret = v4l2_device_register(&pdev->dev, &solo_dev->v4l2_dev);
 	if (ret)
 		goto fail_probe;
--- a/drivers/media/pci/solo6x10/solo6x10.h
+++ b/drivers/media/pci/solo6x10/solo6x10.h
@@ -201,7 +201,6 @@  struct solo_dev {
 	int			nr_ext;
 	u32			irq_mask;
 	u32			motion_mask;
-	spinlock_t		reg_io_lock;
 	struct v4l2_device	v4l2_dev;
 
 	/* tw28xx accounting */
@@ -283,36 +282,13 @@  struct solo_dev {
 
 static inline u32 solo_reg_read(struct solo_dev *solo_dev, int reg)
 {
-	unsigned long flags;
-	u32 ret;
-	u16 val;
-
-	spin_lock_irqsave(&solo_dev->reg_io_lock, flags);
-
-	ret = readl(solo_dev->reg_base + reg);
-	rmb();
-	pci_read_config_word(solo_dev->pdev, PCI_STATUS, &val);
-	rmb();
-
-	spin_unlock_irqrestore(&solo_dev->reg_io_lock, flags);
-
-	return ret;
+	return readl(solo_dev->reg_base + reg);
 }
 
 static inline void solo_reg_write(struct solo_dev *solo_dev, int reg,
 				  u32 data)
 {
-	unsigned long flags;
-	u16 val;
-
-	spin_lock_irqsave(&solo_dev->reg_io_lock, flags);
-
 	writel(data, solo_dev->reg_base + reg);
-	wmb();
-	pci_read_config_word(solo_dev->pdev, PCI_STATUS, &val);
-	rmb();
-
-	spin_unlock_irqrestore(&solo_dev->reg_io_lock, flags);
 }
 
 static inline void solo_irq_on(struct solo_dev *dev, u32 mask)