Commit 45f04e82 authored by Frank Schaefer's avatar Frank Schaefer Committed by Mauro Carvalho Chehab
Browse files

[media] em28xx: fix+improve+unify i2c error handling, debug messages and code comments 



- 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

Signed-off-by: default avatarFrank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent eaf33c40

drivers/media/usb/em28xx/em28xx-core.c

+4 −1
Original line number Diff line number Diff line
@@ -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);

drivers/media/usb/em28xx/em28xx-i2c.c

+85 −31
Original line number Diff line number Diff line
@@ -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)

	if (ret > 0) {

		if (ret == 0x10) {

			return -ENODEV;

	return ret;

		} 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;

	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

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