[media] em28xx: remove GPIO register caching

The GPIO register caching is the result of wrong assumptions and incomplete
knowledge about the GPIO registers and their functionality.
Today, we know that it is not needed.
It is also limited to a single register and therefore incomplete (newer chips
are using multiple registers).
Instead of extending the caching, get rid of it, because it has no real
benefits and just bloats/complicates the code.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 2 insertions, 25 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index a802128ce9c5..fc157af5234a 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -193,23 +193,7 @@ int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16 reg, char *buf,
 
 int em28xx_write_regs(struct em28xx *dev, u16 reg, char *buf, int len)
 {
-	int rc;
-
-	rc = em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
-
-	/* Stores GPO/GPIO values at the cache, if changed
-	   Only write values should be stored, since input on a GPIO
-	   register will return the input bits.
-	   Not sure what happens on reading GPO register.
-	 */
-	if (rc >= 0) {
-		if (reg == dev->reg_gpo_num)
-			dev->reg_gpo = buf[0];
-		else if (reg == dev->reg_gpio_num)
-			dev->reg_gpio = buf[0];
-	}
-
-	return rc;
+	return em28xx_write_regs_req(dev, USB_REQ_GET_STATUS, reg, buf, len);
 }
 EXPORT_SYMBOL_GPL(em28xx_write_regs);
 
@@ -231,14 +215,7 @@ int em28xx_write_reg_bits(struct em28xx *dev, u16 reg, u8 val,
 	int oldval;
 	u8 newval;
 
-	/* Uses cache for gpo/gpio registers */
-	if (reg == dev->reg_gpo_num)
-		oldval = dev->reg_gpo;
-	else if (reg == dev->reg_gpio_num)
-		oldval = dev->reg_gpio;
-	else
-		oldval = em28xx_read_reg(dev, reg);
-
+	oldval = em28xx_read_reg(dev, reg);
 	if (oldval < 0)
 		return oldval;