Commit 29dae457 authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Andi Shyti
Browse files

i2c: i801: Add SMBUS_LEN_SENTINEL 



Add a sentinel length value that is used to check whether we should
read and use the length value provided by the slave device.
This simplifies the currently used checks.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 6ff9d46c

drivers/i2c/busses/i2c-i801.c

+16 −6
Original line number Diff line number Diff line
@@ -205,6 +205,8 @@ 
#define STATUS_FLAGS		(SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR | \

				 STATUS_ERROR_FLAGS)



#define SMBUS_LEN_SENTINEL (I2C_SMBUS_BLOCK_MAX + 1)



/* Older devices have their ID defined in <linux/pci_ids.h> */

#define PCI_DEVICE_ID_INTEL_COMETLAKE_SMBUS		0x02a3

#define PCI_DEVICE_ID_INTEL_COMETLAKE_H_SMBUS		0x06a3
@@ -541,9 +543,12 @@ static int i801_block_transaction_by_block(struct i801_priv *priv, 
static void i801_isr_byte_done(struct i801_priv *priv)

{

	if (priv->is_read) {

		/* For SMBus block reads, length is received with first byte */

		if (((priv->cmd & 0x1c) == I801_BLOCK_DATA) &&

		    (priv->count == 0)) {

		/*

		 * At transfer start i801_smbus_block_transaction() marks

		 * the block length as invalid. Check for this sentinel value

		 * and read the block length from SMBHSTDAT0.

		 */

		if (priv->len == SMBUS_LEN_SENTINEL) {

			priv->len = inb_p(SMBHSTDAT0(priv));

			if (priv->len < 1 || priv->len > I2C_SMBUS_BLOCK_MAX) {

				dev_err(&priv->pci_dev->dev,
@@ -698,8 +703,12 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, 
		if (status)

			return status;



		if (i == 1 && read_write == I2C_SMBUS_READ

		 && command != I2C_SMBUS_I2C_BLOCK_DATA) {

		/*

		 * At transfer start i801_smbus_block_transaction() marks

		 * the block length as invalid. Check for this sentinel value

		 * and read the block length from SMBHSTDAT0.

		 */

		if (len == SMBUS_LEN_SENTINEL) {

			len = inb_p(SMBHSTDAT0(priv));

			if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) {

				dev_err(&priv->pci_dev->dev,
@@ -806,7 +815,8 @@ static int i801_smbus_block_transaction(struct i801_priv *priv, union i2c_smbus_ 
					u8 addr, u8 hstcmd, char read_write, int command)

{

	if (read_write == I2C_SMBUS_READ && command == I2C_SMBUS_BLOCK_DATA)

		data->block[0] = I2C_SMBUS_BLOCK_MAX;

		/* Mark block length as invalid */

		data->block[0] = SMBUS_LEN_SENTINEL;

	else if (data->block[0] < 1 || data->block[0] > I2C_SMBUS_BLOCK_MAX)

		return -EPROTO;