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@xxxxxxxxxxx>
---
drivers/media/usb/em28xx/em28xx-i2c.c | 65 ++++++++++++++++++-----------------
1 file changed, 34 insertions(+), 31 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
index 9e6a11d01858..9fa7ed51e5b1 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)
@@ -74,15 +75,15 @@ 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) {
em28xx_warn("R05 returned 0x%02x: I2C timeout", ret);
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;
@@ -99,9 +100,9 @@ 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)
@@ -118,15 +119,15 @@ 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) {
em28xx_warn("R05 returned 0x%02x: I2C timeout", ret);
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;
@@ -170,7 +171,8 @@ 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;
@@ -193,17 +195,18 @@ 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) {
- em28xx_warn("I2C transfer timeout on writing to addr 0x%02x", addr);
+ if (ret == 0x10) {
+ em28xx_warn("I2C transfer timeout on writing to addr 0x%02x",
+ addr);
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;
}
@@ -214,6 +217,7 @@ 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;
}
@@ -251,21 +255,20 @@ 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) {
- em28xx_warn("I2C transfer timeout on read from addr 0x%02x", addr);
- return -ENODEV;
- } else {
- em28xx_warn("unknown i2c error (status=%i)\n", ret);
- return -EIO;
- }
+ if (ret == 0x10) {
+ em28xx_warn("I2C transfer timeout on read from addr 0x%02x", addr);
+ return -ENODEV;
}
- return len;
+
+ em28xx_warn("unknown i2c error (status=%i)\n", ret);
+ return -EIO;
}
/*
--
1.8.3.1
--
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