Commit 8b1b2ca8 authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Jakub Kicinski
Browse files

net: usb: lan78xx: Improve error handling in EEPROM and OTP operations 



Refine error handling in EEPROM and OTP read/write functions by:
- Return error values immediately upon detection.
- Avoid overwriting correct error codes with `-EIO`.
- Preserve initial error codes as they were appropriate for specific
  failures.
- Use `-ETIMEDOUT` for timeout conditions instead of `-EIO`.

Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241204084142.1152696-7-o.rempel@pengutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 32ee0dc7

drivers/net/usb/lan78xx.c

+152 −88
Original line number Diff line number Diff line
@@ -1000,8 +1000,8 @@ static int lan78xx_wait_eeprom(struct lan78xx_net *dev) 


	do {

		ret = lan78xx_read_reg(dev, E2P_CMD, &val);

		if (unlikely(ret < 0))

			return -EIO;

		if (ret < 0)

			return ret;



		if (!(val & E2P_CMD_EPC_BUSY_) ||

		    (val & E2P_CMD_EPC_TIMEOUT_))
@@ -1011,7 +1011,7 @@ static int lan78xx_wait_eeprom(struct lan78xx_net *dev) 


	if (val & (E2P_CMD_EPC_TIMEOUT_ | E2P_CMD_EPC_BUSY_)) {

		netdev_warn(dev->net, "EEPROM read operation timeout");

		return -EIO;

		return -ETIMEDOUT;

	}



	return 0;
@@ -1025,8 +1025,8 @@ static int lan78xx_eeprom_confirm_not_busy(struct lan78xx_net *dev) 


	do {

		ret = lan78xx_read_reg(dev, E2P_CMD, &val);

		if (unlikely(ret < 0))

			return -EIO;

		if (ret < 0)

			return ret;



		if (!(val & E2P_CMD_EPC_BUSY_))

			return 0;
@@ -1035,75 +1035,81 @@ static int lan78xx_eeprom_confirm_not_busy(struct lan78xx_net *dev) 
	} while (!time_after(jiffies, start_time + HZ));



	netdev_warn(dev->net, "EEPROM is busy");

	return -EIO;

	return -ETIMEDOUT;

}



static int lan78xx_read_raw_eeprom(struct lan78xx_net *dev, u32 offset,

				   u32 length, u8 *data)

{

	u32 val;

	u32 saved;

	u32 val, saved;

	int i, ret;

	int retval;



	/* depends on chip, some EEPROM pins are muxed with LED function.

	 * disable & restore LED function to access EEPROM.

	 */

	ret = lan78xx_read_reg(dev, HW_CFG, &val);

	if (ret < 0)

		return ret;



	saved = val;

	if (dev->chipid == ID_REV_CHIP_ID_7800_) {

		val &= ~(HW_CFG_LED1_EN_ | HW_CFG_LED0_EN_);

		ret = lan78xx_write_reg(dev, HW_CFG, val);

		if (ret < 0)

			return ret;

	}



	retval = lan78xx_eeprom_confirm_not_busy(dev);

	if (retval)

		return retval;

	ret = lan78xx_eeprom_confirm_not_busy(dev);

	if (ret == -ETIMEDOUT)

		goto read_raw_eeprom_done;

	/* If USB fails, there is nothing to do */

	if (ret < 0)

		return ret;



	for (i = 0; i < length; i++) {

		val = E2P_CMD_EPC_BUSY_ | E2P_CMD_EPC_CMD_READ_;

		val |= (offset & E2P_CMD_EPC_ADDR_MASK_);

		ret = lan78xx_write_reg(dev, E2P_CMD, val);

		if (unlikely(ret < 0)) {

			retval = -EIO;

			goto exit;

		}

		if (ret < 0)

			return ret;



		retval = lan78xx_wait_eeprom(dev);

		if (retval < 0)

			goto exit;

		ret = lan78xx_wait_eeprom(dev);

		/* Looks like not USB specific error, try to recover */

		if (ret == -ETIMEDOUT)

			goto read_raw_eeprom_done;

		/* If USB fails, there is nothing to do */

		if (ret < 0)

			return ret;



		ret = lan78xx_read_reg(dev, E2P_DATA, &val);

		if (unlikely(ret < 0)) {

			retval = -EIO;

			goto exit;

		}

		if (ret < 0)

			return ret;



		data[i] = val & 0xFF;

		offset++;

	}



	retval = 0;

exit:

read_raw_eeprom_done:

	if (dev->chipid == ID_REV_CHIP_ID_7800_)

		ret = lan78xx_write_reg(dev, HW_CFG, saved);

		return lan78xx_write_reg(dev, HW_CFG, saved);



	return retval;

	return 0;

}



static int lan78xx_read_eeprom(struct lan78xx_net *dev, u32 offset,

			       u32 length, u8 *data)

{

	u8 sig;

	int ret;

	u8 sig;



	ret = lan78xx_read_raw_eeprom(dev, 0, 1, &sig);

	if ((ret == 0) && (sig == EEPROM_INDICATOR))

		ret = lan78xx_read_raw_eeprom(dev, offset, length, data);

	else

		ret = -EINVAL;



	if (ret < 0)

		return ret;



	if (sig != EEPROM_INDICATOR)

		return -ENODATA;



	return lan78xx_read_raw_eeprom(dev, offset, length, data);

}



static int lan78xx_write_raw_eeprom(struct lan78xx_net *dev, u32 offset,
@@ -1112,113 +1118,144 @@ static int lan78xx_write_raw_eeprom(struct lan78xx_net *dev, u32 offset, 
	u32 val;

	u32 saved;

	int i, ret;

	int retval;



	/* depends on chip, some EEPROM pins are muxed with LED function.

	 * disable & restore LED function to access EEPROM.

	 */

	ret = lan78xx_read_reg(dev, HW_CFG, &val);

	if (ret < 0)

		return ret;



	saved = val;

	if (dev->chipid == ID_REV_CHIP_ID_7800_) {

		val &= ~(HW_CFG_LED1_EN_ | HW_CFG_LED0_EN_);

		ret = lan78xx_write_reg(dev, HW_CFG, val);

		if (ret < 0)

			return ret;

	}



	retval = lan78xx_eeprom_confirm_not_busy(dev);

	if (retval)

		goto exit;

	ret = lan78xx_eeprom_confirm_not_busy(dev);

	/* Looks like not USB specific error, try to recover */

	if (ret == -ETIMEDOUT)

		goto write_raw_eeprom_done;

	/* If USB fails, there is nothing to do */

	if (ret < 0)

		return ret;



	/* Issue write/erase enable command */

	val = E2P_CMD_EPC_BUSY_ | E2P_CMD_EPC_CMD_EWEN_;

	ret = lan78xx_write_reg(dev, E2P_CMD, val);

	if (unlikely(ret < 0)) {

		retval = -EIO;

		goto exit;

	}

	if (ret < 0)

		return ret;



	retval = lan78xx_wait_eeprom(dev);

	if (retval < 0)

		goto exit;

	ret = lan78xx_wait_eeprom(dev);

	/* Looks like not USB specific error, try to recover */

	if (ret == -ETIMEDOUT)

		goto write_raw_eeprom_done;

	/* If USB fails, there is nothing to do */

	if (ret < 0)

		return ret;



	for (i = 0; i < length; i++) {

		/* Fill data register */

		val = data[i];

		ret = lan78xx_write_reg(dev, E2P_DATA, val);

		if (ret < 0) {

			retval = -EIO;

			goto exit;

		}

		if (ret < 0)

			return ret;



		/* Send "write" command */

		val = E2P_CMD_EPC_BUSY_ | E2P_CMD_EPC_CMD_WRITE_;

		val |= (offset & E2P_CMD_EPC_ADDR_MASK_);

		ret = lan78xx_write_reg(dev, E2P_CMD, val);

		if (ret < 0) {

			retval = -EIO;

			goto exit;

		}

		if (ret < 0)

			return ret;



		retval = lan78xx_wait_eeprom(dev);

		if (retval < 0)

			goto exit;

		ret = lan78xx_wait_eeprom(dev);

		/* Looks like not USB specific error, try to recover */

		if (ret == -ETIMEDOUT)

			goto write_raw_eeprom_done;

		/* If USB fails, there is nothing to do */

		if (ret < 0)

			return ret;



		offset++;

	}



	retval = 0;

exit:

write_raw_eeprom_done:

	if (dev->chipid == ID_REV_CHIP_ID_7800_)

		ret = lan78xx_write_reg(dev, HW_CFG, saved);

		return lan78xx_write_reg(dev, HW_CFG, saved);



	return retval;

	return 0;

}



static int lan78xx_read_raw_otp(struct lan78xx_net *dev, u32 offset,

				u32 length, u8 *data)

{

	int i;

	u32 buf;

	unsigned long timeout;

	int ret, i;

	u32 buf;



	lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

	ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

	if (ret < 0)

		return ret;



	if (buf & OTP_PWR_DN_PWRDN_N_) {

		/* clear it and wait to be cleared */

		lan78xx_write_reg(dev, OTP_PWR_DN, 0);

		ret = lan78xx_write_reg(dev, OTP_PWR_DN, 0);

		if (ret < 0)

			return ret;



		timeout = jiffies + HZ;

		do {

			usleep_range(1, 10);

			lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

			ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

			if (ret < 0)

				return ret;



			if (time_after(jiffies, timeout)) {

				netdev_warn(dev->net,

					    "timeout on OTP_PWR_DN");

				return -EIO;

				return -ETIMEDOUT;

			}

		} while (buf & OTP_PWR_DN_PWRDN_N_);

	}



	for (i = 0; i < length; i++) {

		lan78xx_write_reg(dev, OTP_ADDR1,

		ret = lan78xx_write_reg(dev, OTP_ADDR1,

					((offset + i) >> 8) & OTP_ADDR1_15_11);

		lan78xx_write_reg(dev, OTP_ADDR2,

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_ADDR2,

					((offset + i) & OTP_ADDR2_10_3));

		if (ret < 0)

			return ret;



		lan78xx_write_reg(dev, OTP_FUNC_CMD, OTP_FUNC_CMD_READ_);

		lan78xx_write_reg(dev, OTP_CMD_GO, OTP_CMD_GO_GO_);

		ret = lan78xx_write_reg(dev, OTP_FUNC_CMD, OTP_FUNC_CMD_READ_);

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_CMD_GO, OTP_CMD_GO_GO_);

		if (ret < 0)

			return ret;



		timeout = jiffies + HZ;

		do {

			udelay(1);

			lan78xx_read_reg(dev, OTP_STATUS, &buf);

			ret = lan78xx_read_reg(dev, OTP_STATUS, &buf);

			if (ret < 0)

				return ret;



			if (time_after(jiffies, timeout)) {

				netdev_warn(dev->net,

					    "timeout on OTP_STATUS");

				return -EIO;

				return -ETIMEDOUT;

			}

		} while (buf & OTP_STATUS_BUSY_);



		lan78xx_read_reg(dev, OTP_RD_DATA, &buf);

		ret = lan78xx_read_reg(dev, OTP_RD_DATA, &buf);

		if (ret < 0)

			return ret;



		data[i] = (u8)(buf & 0xFF);

	}
@@ -1232,45 +1269,72 @@ static int lan78xx_write_raw_otp(struct lan78xx_net *dev, u32 offset, 
	int i;

	u32 buf;

	unsigned long timeout;

	int ret;



	lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

	ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

	if (ret < 0)

		return ret;



	if (buf & OTP_PWR_DN_PWRDN_N_) {

		/* clear it and wait to be cleared */

		lan78xx_write_reg(dev, OTP_PWR_DN, 0);

		ret = lan78xx_write_reg(dev, OTP_PWR_DN, 0);

		if (ret < 0)

			return ret;



		timeout = jiffies + HZ;

		do {

			udelay(1);

			lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

			ret = lan78xx_read_reg(dev, OTP_PWR_DN, &buf);

			if (ret < 0)

				return ret;



			if (time_after(jiffies, timeout)) {

				netdev_warn(dev->net,

					    "timeout on OTP_PWR_DN completion");

				return -EIO;

				return -ETIMEDOUT;

			}

		} while (buf & OTP_PWR_DN_PWRDN_N_);

	}



	/* set to BYTE program mode */

	lan78xx_write_reg(dev, OTP_PRGM_MODE, OTP_PRGM_MODE_BYTE_);

	ret = lan78xx_write_reg(dev, OTP_PRGM_MODE, OTP_PRGM_MODE_BYTE_);

	if (ret < 0)

		return ret;



	for (i = 0; i < length; i++) {

		lan78xx_write_reg(dev, OTP_ADDR1,

		ret = lan78xx_write_reg(dev, OTP_ADDR1,

					((offset + i) >> 8) & OTP_ADDR1_15_11);

		lan78xx_write_reg(dev, OTP_ADDR2,

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_ADDR2,

					((offset + i) & OTP_ADDR2_10_3));

		lan78xx_write_reg(dev, OTP_PRGM_DATA, data[i]);

		lan78xx_write_reg(dev, OTP_TST_CMD, OTP_TST_CMD_PRGVRFY_);

		lan78xx_write_reg(dev, OTP_CMD_GO, OTP_CMD_GO_GO_);

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_PRGM_DATA, data[i]);

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_TST_CMD, OTP_TST_CMD_PRGVRFY_);

		if (ret < 0)

			return ret;



		ret = lan78xx_write_reg(dev, OTP_CMD_GO, OTP_CMD_GO_GO_);

		if (ret < 0)

			return ret;



		timeout = jiffies + HZ;

		do {

			udelay(1);

			lan78xx_read_reg(dev, OTP_STATUS, &buf);

			ret = lan78xx_read_reg(dev, OTP_STATUS, &buf);

			if (ret < 0)

				return ret;



			if (time_after(jiffies, timeout)) {

				netdev_warn(dev->net,

					    "Timeout on OTP_STATUS completion");

				return -EIO;

				return -ETIMEDOUT;

			}

		} while (buf & OTP_STATUS_BUSY_);

	}