From: Jean Delvare Date: Sat, 13 Mar 2010 19:56:53 +0000 (+0100) Subject: i2c-i801: Don't use the block buffer for I2C block writes X-Git-Tag: firefly_0821_release~10186^2~2019 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cde4ff84e046eaed345bde28aa2e5529b5124d02;p=firefly-linux-kernel-4.4.55.git i2c-i801: Don't use the block buffer for I2C block writes commit c074c39d62306efa5ba7c69c1a1531bc7333d252 upstream. Experience has shown that the block buffer can only be used for SMBus (not I2C) block transactions, even though the datasheet doesn't mention this limitation. Reported-by: Felix Rubinstein Signed-off-by: Jean Delvare Cc: Oleg Ryjkov Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 55edcfe5b851..4d73fcfbbe9a 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -415,9 +415,11 @@ static int i801_block_transaction(union i2c_smbus_data *data, char read_write, data->block[0] = 32; /* max for SMBus block reads */ } + /* Experience has shown that the block buffer can only be used for + SMBus (not I2C) block transactions, even though the datasheet + doesn't mention this limitation. */ if ((i801_features & FEATURE_BLOCK_BUFFER) - && !(command == I2C_SMBUS_I2C_BLOCK_DATA - && read_write == I2C_SMBUS_READ) + && command != I2C_SMBUS_I2C_BLOCK_DATA && i801_set_block_buffer_mode() == 0) result = i801_block_transaction_by_block(data, read_write, hwpec);