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

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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>
This commit is contained in:
Mauro Carvalho Chehab 2014-01-04 05:42:11 -03:00
parent 5022a20886
commit 4b83626ac2
1 changed files with 31 additions and 30 deletions
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61
drivers/media/usb/em28xx/em28xx-i2c.c
View file

@ -26,6 +26,7 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/usb.h> #include <linux/usb.h>
#include <linux/i2c.h> #include <linux/i2c.h>
#include <linux/jiffies.h>
#include "em28xx.h" #include "em28xx.h"
#include "tuner-xc2028.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) 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 ret;
int write_timeout;
u8 b2[6]; u8 b2[6];
if (len < 1 || len > 4) 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; return (ret < 0) ? ret : -EIO;
} }
/* wait for completion */ /* wait for completion */
for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; while (time_is_after_jiffies(timeout)) {
write_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05); ret = dev->em28xx_read_reg(dev, 0x05);
if (ret == 0x80 + len - 1) { if (ret == 0x80 + len - 1)
return len; return len;
} else if (ret == 0x94 + len - 1) { if (ret == 0x94 + len - 1) {
return -ENODEV; return -ENODEV;
} else if (ret < 0) { }
if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
ret); ret);
return 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) 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]; u8 buf2[4];
int ret; int ret;
int read_timeout;
int i; int i;
if (len < 1 || len > 4) 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 */ /* wait for completion */
for (read_timeout = EM2800_I2C_XFER_TIMEOUT; read_timeout > 0; while (time_is_after_jiffies(timeout)) {
read_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05); ret = dev->em28xx_read_reg(dev, 0x05);
if (ret == 0x84 + len - 1) { if (ret == 0x84 + len - 1)
break; break;
} else if (ret == 0x94 + len - 1) { if (ret == 0x94 + len - 1) {
return -ENODEV; return -ENODEV;
} else if (ret < 0) { }
if (ret < 0) {
em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n",
ret); ret);
return 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, static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
u16 len, int stop) 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) if (len < 1 || len > 64)
return -EOPNOTSUPP; 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 */ /* wait for completion */
for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; while (time_is_after_jiffies(timeout)) {
write_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05); ret = dev->em28xx_read_reg(dev, 0x05);
if (ret == 0) { /* success */ if (ret == 0) /* success */
return len; return len;
} else if (ret == 0x10) { if (ret == 0x10) {
return -ENODEV; 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); ret);
return ret; return ret;
} }
@ -211,6 +213,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf,
* (even with high payload) ... * (even with high payload) ...
*/ */
} }
em28xx_warn("write to i2c device at 0x%x timed out\n", addr); em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
return -EIO; 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 */ /* Check success of the i2c operation */
ret = dev->em28xx_read_reg(dev, 0x05); ret = dev->em28xx_read_reg(dev, 0x05);
if (ret == 0) /* success */
return len;
if (ret < 0) { 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); ret);
return ret; return ret;
} }
if (ret > 0) { if (ret == 0x10)
if (ret == 0x10) { return -ENODEV;
return -ENODEV;
} else { em28xx_warn("unknown i2c error (status=%i)\n", ret);
em28xx_warn("unknown i2c error (status=%i)\n", ret); return -EIO;
return -EIO;
}
}
return len;
} }
/* /*