5.4-stable review patch. If anyone has any objections, please let me know.
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From: Heiner Kallweit hkallweit1@gmail.com
[ Upstream commit 1e1d6582f483a4dba4ea03445e6f2f05d9de5bcf ]
If FEATURE_BLOCK_BUFFER is set then bit SMBAUXCTL_E32B is supported and there's no benefit in reading it back. Origin of this check seems to be 14 yrs ago when people were not completely sure which chip versions support the block buffer mode.
Signed-off-by: Heiner Kallweit hkallweit1@gmail.com Reviewed-by: Jean Delvare jdelvare@suse.de Tested-by: Jean Delvare jdelvare@suse.de Signed-off-by: Wolfram Sang wsa@kernel.org Stable-dep-of: c1c9d0f6f7f1 ("i2c: i801: Fix block process call transactions") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-i801.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 50c972b3efe0..21ed6d98c048 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -528,9 +528,11 @@ static int i801_block_transaction_by_block(struct i801_priv *priv, return -EOPNOTSUPP; }
+ /* Set block buffer mode */ + outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv)); + inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
- /* Use 32-byte buffer to process this transaction */ if (read_write == I2C_SMBUS_WRITE) { len = data->block[0]; outb_p(len, SMBHSTDAT0(priv)); @@ -768,14 +770,6 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, return i801_check_post(priv, status); }
-static int i801_set_block_buffer_mode(struct i801_priv *priv) -{ - outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv)); - if ((inb_p(SMBAUXCTL(priv)) & SMBAUXCTL_E32B) == 0) - return -EIO; - return 0; -} - /* Block transaction function */ static int i801_block_transaction(struct i801_priv *priv, union i2c_smbus_data *data, char read_write, @@ -805,9 +799,8 @@ static int i801_block_transaction(struct i801_priv *priv, /* 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 ((priv->features & FEATURE_BLOCK_BUFFER) - && command != I2C_SMBUS_I2C_BLOCK_DATA - && i801_set_block_buffer_mode(priv) == 0) + if ((priv->features & FEATURE_BLOCK_BUFFER) && + command != I2C_SMBUS_I2C_BLOCK_DATA) result = i801_block_transaction_by_block(priv, data, read_write, command, hwpec);