From e63b009d6e772e3fe6df39345ca2f8949d4497e6 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sat, 4 Jan 2014 05:42:11 -0300 Subject: [PATCH] [media] em28xx-i2c: Fix error code for I2C error transfers Follow the error codes for I2C as described at Documentation/i2c/fault-codes. In the case of the I2C status register (0x05), this is mapped into: - ENXIO - when reg 05 returns 0x10 - ETIMEDOUT - when the device is not temporarily not responding (e. g. reg 05 returning something not 0x10 or 0x00) - EIO - for generic I/O errors that don't fit into the above. In the specific case of 0-byte reads, used only during I2C device probing, it keeps returning -ENODEV. TODO: return EBUSY when reg 05 returns 0x20 on em2874 and upper. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-i2c.c | 37 +++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c index 342f35a..76f9566 100644 --- a/drivers/media/usb/em28xx/em28xx-i2c.c +++ b/drivers/media/usb/em28xx/em28xx-i2c.c @@ -80,7 +80,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) if (ret == 0x80 + len - 1) return len; if (ret == 0x94 + len - 1) { - return -ENODEV; + return -ENXIO; } if (ret < 0) { em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", @@ -90,7 +90,7 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) msleep(5); } em28xx_warn("write to i2c device at 0x%x timed out\n", addr); - return -EIO; + return -ETIMEDOUT; } /* @@ -123,7 +123,7 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) if (ret == 0x84 + len - 1) break; if (ret == 0x94 + len - 1) { - return -ENODEV; + return -ENXIO; } if (ret < 0) { em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", @@ -199,7 +199,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, if (ret == 0) /* success */ return len; if (ret == 0x10) { - return -ENODEV; + return -ENXIO; } if (ret < 0) { em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", @@ -213,9 +213,8 @@ 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; + em28xx_warn("write to i2c device at 0x%x timed out (status=%i)\n", addr, ret); + return -ETIMEDOUT; } /* @@ -245,7 +244,7 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len) * bytes if we are on bus B AND there was no write attempt to the * specified slave address before AND no device is present at the * requested slave address. - * Anyway, the next check will fail with -ENODEV in this case, so avoid + * Anyway, the next check will fail with -ENXIO in this case, so avoid * spamming the system log on device probing and do nothing here. */ @@ -259,10 +258,10 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len) return ret; } if (ret == 0x10) - return -ENODEV; + return -ENXIO; em28xx_warn("unknown i2c error (status=%i)\n", ret); - return -EIO; + return -ETIMEDOUT; } /* @@ -318,7 +317,7 @@ static int em25xx_bus_B_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, if (!ret) return len; else if (ret > 0) - return -ENODEV; + return -ENXIO; return ret; /* @@ -356,7 +355,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, * bytes if we are on bus B AND there was no write attempt to the * specified slave address before AND no device is present at the * requested slave address. - * Anyway, the next check will fail with -ENODEV in this case, so avoid + * Anyway, the next check will fail with -ENXIO in this case, so avoid * spamming the system log on device probing and do nothing here. */ @@ -369,7 +368,7 @@ static int em25xx_bus_B_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, if (!ret) return len; else if (ret > 0) - return -ENODEV; + return -ENXIO; return ret; /* @@ -410,7 +409,7 @@ static inline int i2c_check_for_device(struct em28xx_i2c_bus *i2c_bus, u16 addr) rc = em2800_i2c_check_for_device(dev, addr); else if (i2c_bus->algo_type == EM28XX_I2C_ALGO_EM25XX_BUS_B) rc = em25xx_bus_B_check_for_device(dev, addr); - if (rc == -ENODEV) { + if (rc == -ENXIO) { if (i2c_debug) printk(" no device\n"); } @@ -498,11 +497,15 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap, (msgs[i].flags & I2C_M_RD) ? "read" : "write", i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len); - if (!msgs[i].len) { /* no len: check only for device presence */ + if (!msgs[i].len) { + /* + * no len: check only for device presence + * This code is only called during device probe. + */ rc = i2c_check_for_device(i2c_bus, addr); - if (rc == -ENODEV) { + if (rc == -ENXIO) { rt_mutex_unlock(&dev->i2c_bus_lock); - return rc; + return -ENODEV; } } else if (msgs[i].flags & I2C_M_RD) { /* read bytes */ -- 2.7.4