From 09e4a3bbdac45a97f7f496a8f6b436bd8e82d6cf Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sat, 4 Jan 2014 05:42:11 -0300 Subject: [PATCH] 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 --- drivers/media/usb/em28xx/em28xx-i2c.c | 61 ++++++++++++++++++----------------- 1 file changed, 31 insertions(+), 30 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c index c4ff973..91f9f0a 100644 --- a/drivers/media/usb/em28xx/em28xx-i2c.c +++ b/drivers/media/usb/em28xx/em28xx-i2c.c @@ -26,6 +26,7 @@ #include #include #include +#include #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; } /* -- 2.7.4