[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>

1 files changed, 31 insertions, 30 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index f2d5f8a7175b..0af6d790660f 100644
--- 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;
 }
 
 /*