upstream: [media] em28xx: convert i2c wait completion logic to use jiffies

The I2C wait completion/timeout logic currently assumes that
msleep(5) will wait exaclty 5 ms. This is not true at all,
as it depends on CONFIG_HZ.

Convert it to use jiffies, in order to not wait for more time
than needed.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index c4ff973..91f9f0a 100644 (file)
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -26,6 +26,7 @@
 #include <linux/kernel.h>
 #include <linux/usb.h>
 #include <linux/i2c.h>
+#include <linux/jiffies.h>
 
 #include "em28xx.h"
 #include "tuner-xc2028.h"
@@ -48,8 +49,8 @@ MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  */
 static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
 {
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT);
        int ret;
-       int write_timeout;
        u8 b2[6];
 
        if (len < 1 || len > 4)
@@ -74,14 +75,14 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
                return (ret < 0) ? ret : -EIO;
        }
        /* wait for completion */
-       for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
-            write_timeout -= 5) {
+       while (time_is_after_jiffies(timeout)) {
                ret = dev->em28xx_read_reg(dev, 0x05);
-               if (ret == 0x80 + len - 1) {
+               if (ret == 0x80 + len - 1)
                        return len;
-               } else if (ret == 0x94 + len - 1) {
+               if (ret == 0x94 + len - 1) {
                        return -ENODEV;
-               } else if (ret < 0) {
+               }
+               if (ret < 0) {
                        em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
                                    ret);
                        return ret;
@@ -98,9 +99,9 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
  */
 static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
 {
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT);
        u8 buf2[4];
        int ret;
-       int read_timeout;
        int i;
 
        if (len < 1 || len > 4)
@@ -117,14 +118,14 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len)
        }
 
        /* wait for completion */
-       for (read_timeout = EM2800_I2C_XFER_TIMEOUT; read_timeout > 0;
-            read_timeout -= 5) {
+       while (time_is_after_jiffies(timeout)) {
                ret = dev->em28xx_read_reg(dev, 0x05);
-               if (ret == 0x84 + len - 1) {
+               if (ret == 0x84 + len - 1)
                        break;
-               } else if (ret == 0x94 + len - 1) {
+               if (ret == 0x94 + len - 1) {
                        return -ENODEV;
-               } else if (ret < 0) {
+               }
+               if (ret < 0) {
                        em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
                                    ret);
                        return ret;
@@ -168,7 +169,8 @@ static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr)
 static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
                                 u16 len, int stop)
 {
-       int write_timeout, ret;
+       unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT);
+       int ret;
 
        if (len < 1 || len > 64)
                return -EOPNOTSUPP;
@@ -191,16 +193,16 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
                }
        }
 
-       /* Check success of the i2c operation */
-       for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
-            write_timeout -= 5) {
+       /* wait for completion */
+       while (time_is_after_jiffies(timeout)) {
                ret = dev->em28xx_read_reg(dev, 0x05);
-               if (ret == 0) { /* success */
+               if (ret == 0) /* success */
                        return len;
-               } else if (ret == 0x10) {
+               if (ret == 0x10) {
                        return -ENODEV;
-               } else if (ret < 0) {
-                       em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n",
+               }
+               if (ret < 0) {
+                       em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
                                    ret);
                        return ret;
                }
@@ -211,6 +213,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
                 * (even with high payload) ...
                 */
        }
+
        em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
        return -EIO;
 }
@@ -248,20 +251,18 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len)
 
        /* Check success of the i2c operation */
        ret = dev->em28xx_read_reg(dev, 0x05);
+       if (ret == 0) /* success */
+               return len;
        if (ret < 0) {
-               em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n",
+               em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
                            ret);
                return ret;
        }
-       if (ret > 0) {
-               if (ret == 0x10) {
-                       return -ENODEV;
-               } else {
-                       em28xx_warn("unknown i2c error (status=%i)\n", ret);
-                       return -EIO;
-               }
-       }
-       return len;
+       if (ret == 0x10)
+               return -ENODEV;
+
+       em28xx_warn("unknown i2c error (status=%i)\n", ret);
+       return -EIO;
 }
 
 /*