Commit 08e5138a authored by Heiner Kallweit's avatar Heiner Kallweit Committed by Greg Kroah-Hartman
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eeprom: ee1004: Improve check for SMBUS features 



We have to read 512 bytes only, therefore read performance isn't really
a concern. Don't bother the user if i2c block read isn't supported.

For i2c_smbus_read_i2c_block_data_or_emulated() to work it's sufficient
if I2C_FUNC_SMBUS_READ_I2C_BLOCK or I2C_FUNC_SMBUS_READ_BYTE_DATA is
supported. Therefore remove the check for I2C_FUNC_SMBUS_READ_WORD_DATA.

In addition check for I2C_FUNC_SMBUS_WRITE_BYTE (included in
I2C_FUNC_SMBUS_BYTE) which is needed for setting the page.

Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/840c668e-6310-e933-e50e-5abeaecfb39c@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b97ba92e

drivers/misc/eeprom/ee1004.c

+4 −18
Original line number Diff line number Diff line
@@ -167,23 +167,13 @@ static int ee1004_probe(struct i2c_client *client, 
			const struct i2c_device_id *id)

{

	int err, cnr = 0;

	const char *slow = NULL;



	/* Make sure we can operate on this adapter */

	if (!i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_READ_BYTE |

				     I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {

		if (i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_READ_BYTE |

				     I2C_FUNC_SMBUS_READ_WORD_DATA))

			slow = "word";

		else if (i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_READ_BYTE |

				     I2C_FUNC_SMBUS_READ_BYTE_DATA))

			slow = "byte";

		else

				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_I2C_BLOCK) &&

	    !i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_BYTE_DATA))

		return -EPFNOSUPPORT;

	}



	/* Use 2 dummy devices for page select command */

	mutex_lock(&ee1004_bus_lock);
@@ -218,10 +208,6 @@ static int ee1004_probe(struct i2c_client *client, 
	dev_info(&client->dev,

		 "%u byte EE1004-compliant SPD EEPROM, read-only\n",

		 EE1004_EEPROM_SIZE);

	if (slow)

		dev_notice(&client->dev,

			   "Falling back to %s reads, performance will suffer\n",

			   slow);



	return 0;