- do not pass USB specific error codes to userspace/i2c-subsystem
- unify the returned error codes and make them compliant with
the i2c subsystem spec
- check number of actually transferred bytes (via USB) everywehere
- fix/improve debug messages
- improve code comments
Changelog:
v2: removed i2c address type/range check as requested by Antti Palosaari
v3: added comment that explains the reasons for the message size restrictions
on em28xx devices
Signed-off-by: Frank Schäfer <fschaefer....@googlemail.com>
---
drivers/media/usb/em28xx/em28xx-core.c | 5 +-
drivers/media/usb/em28xx/em28xx-i2c.c | 116 +++++++++++++++++++++++---------
2 Dateien geändert, 89 Zeilen hinzugefügt(+), 32 Zeilen entfernt(-)
diff --git a/drivers/media/usb/em28xx/em28xx-core.c
b/drivers/media/usb/em28xx/em28xx-core.c
index 6916e87..80f87bb 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -101,7 +101,7 @@ int em28xx_read_reg_req_len(struct em28xx *dev, u8 req, u16
reg,
if (reg_debug)
printk(" failed!\n");
mutex_unlock(&dev->ctrl_urb_lock);
- return ret;
+ return usb_translate_errors(ret);
}
if (len)
@@ -182,6 +182,9 @@ int em28xx_write_regs_req(struct em28xx *dev, u8 req, u16
reg, char *buf,
0x0000, reg, dev->urb_buf, len, HZ);
mutex_unlock(&dev->ctrl_urb_lock);
+ if (ret < 0)
+ return usb_translate_errors(ret);
+
if (dev->wait_after_write)
msleep(dev->wait_after_write);
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c
b/drivers/media/usb/em28xx/em28xx-i2c.c
index 1994083..3ff682e 100644
--- a/drivers/media/usb/em28xx/em28xx-i2c.c
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -76,18 +76,26 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8
addr, u8 *buf, u16 len)
/* trigger write */
ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
if (ret != 2 + len) {
- em28xx_warn("writing to i2c device failed (error=%i)\n", ret);
- return -EIO;
+ em28xx_warn("failed to trigger write to i2c address 0x%x "
+ "(error=%i)\n", addr, ret);
+ return (ret < 0) ? ret : -EIO;
}
/* wait for completion */
for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
write_timeout -= 5) {
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) {
+ return -ENODEV;
+ } else if (ret < 0) {
+ em28xx_warn("failed to get i2c transfer status from "
+ "bridge register (error=%i)\n", ret);
+ return ret;
+ }
msleep(5);
}
- em28xx_warn("i2c write timed out\n");
+ em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
return -EIO;
}
@@ -168,24 +176,48 @@ 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 wrcount = 0;
int write_timeout, ret;
if (len < 1 || len > 64)
return -EOPNOTSUPP;
+ /* NOTE: limited by the USB ctrl message constraints
+ * Zero length reads always succeed, even if no device is connected */
- wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
+ /* Write to i2c device */
+ ret = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
+ if (ret != len) {
+ if (ret < 0) {
+ em28xx_warn("writing to i2c device at 0x%x failed "
+ "(error=%i)\n", addr, ret);
+ return ret;
+ } else {
+ em28xx_warn("%i bytes write to i2c device at 0x%x "
+ "requested, but %i bytes written\n",
+ len, addr, ret);
+ return -EIO;
+ }
+ }
- /* Seems to be required after a write */
+ /* Check success of the i2c operation */
for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0;
write_timeout -= 5) {
ret = dev->em28xx_read_reg(dev, 0x05);
- if (!ret)
- break;
+ if (ret == 0) { /* success */
+ return len;
+ } else if (ret == 0x10) {
+ return -ENODEV;
+ } else if (ret < 0) {
+ em28xx_warn("failed to read i2c transfer status from "
+ "bridge (error=%i)\n", ret);
+ return ret;
+ }
msleep(5);
+ /* NOTE: do we really have to wait for success ?
+ Never seen anything else than 0x00 or 0x10
+ (even with high payload) ... */
}
-
- return wrcount;
+ em28xx_warn("write to i2c device at 0x%x timed out\n", addr);
+ return -EIO;
}
/*
@@ -198,15 +230,40 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16
addr, u8 *buf, u16 len)
if (len < 1 || len > 64)
return -EOPNOTSUPP;
+ /* NOTE: limited by the USB ctrl message constraints
+ * Zero length reads always succeed, even if no device is connected */
+ /* Read data from i2c device */
ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
+ if (ret != len) {
+ if (ret < 0) {
+ em28xx_warn("reading from i2c device at 0x%x failed "
+ "(error=%i)\n", addr, ret);
+ return ret;
+ } else {
+ em28xx_warn("%i bytes requested from i2c device at "
+ "0x%x, but %i bytes received\n",
+ len, addr, ret);
+ return -EIO;
+ }
+ }
+
+ /* Check success of the i2c operation */
+ ret = dev->em28xx_read_reg(dev, 0x05);
if (ret < 0) {
- em28xx_warn("reading i2c device failed (error=%i)\n", ret);
+ em28xx_warn("failed to read i2c transfer status from "
+ "bridge (error=%i)\n", ret);
return ret;
}
- if (dev->em28xx_read_reg(dev, 0x5) != 0)
- return -ENODEV;
- return ret;
+ if (ret > 0) {
+ if (ret == 0x10) {
+ return -ENODEV;
+ } else {
+ em28xx_warn("unknown i2c error (status=%i)\n", ret);
+ return -EIO;
+ }
+ }
+ return len;
}
/*
@@ -216,15 +273,12 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16
addr, u8 *buf, u16 len)
static int em28xx_i2c_check_for_device(struct em28xx *dev, u16 addr)
{
int ret;
+ u8 buf;
- ret = dev->em28xx_read_reg_req(dev, 2, addr);
- if (ret < 0) {
- em28xx_warn("reading from i2c device failed (error=%i)\n", ret);
- return ret;
- }
- if (dev->em28xx_read_reg(dev, 0x5) != 0)
- return -ENODEV;
- return 0;
+ ret = em28xx_i2c_recv_bytes(dev, addr, &buf, 1);
+ if (ret == 1)
+ return 0;
+ return (ret < 0) ? ret : -EIO;
}
/*
@@ -249,11 +303,11 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
rc = em2800_i2c_check_for_device(dev, addr);
else
rc = em28xx_i2c_check_for_device(dev, addr);
- if (rc < 0) {
- dprintk2(2, " no device\n");
+ if (rc == -ENODEV) {
+ if (i2c_debug >= 2)
+ printk(" no device\n");
return rc;
}
-
} else if (msgs[i].flags & I2C_M_RD) {
/* read bytes */
if (dev->board.is_em2800)
@@ -284,16 +338,16 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
msgs[i].len,
i == num - 1);
}
- if (rc < 0)
- goto err;
+ if (rc < 0) {
+ if (i2c_debug >= 2)
+ printk(" ERROR: %i\n", rc);
+ return rc;
+ }
if (i2c_debug >= 2)
printk("\n");
}
return num;
-err:
- dprintk2(2, " ERROR: %i\n", rc);
- return rc;
}
/* based on linux/sunrpc/svcauth.h and linux/hash.h
--
1.7.10.4
--
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