This is a note to let you know that I've just added the patch titled
i2c: i801: Fix block process call transactions
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
i2c-i801-fix-block-process-call-transactions.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d30a9b5ea66051dc912b82d2d11a379f1271cfe7
Author: Jean Delvare <jdelvare@xxxxxxx>
Date: Wed Feb 14 15:59:39 2024 +0100
i2c: i801: Fix block process call transactions
[ Upstream commit c1c9d0f6f7f1dbf29db996bd8e166242843a5f21 ]
According to the Intel datasheets, software must reset the block
buffer index twice for block process call transactions: once before
writing the outgoing data to the buffer, and once again before
reading the incoming data from the buffer.
The driver is currently missing the second reset, causing the wrong
portion of the block buffer to be read.
Signed-off-by: Jean Delvare <jdelvare@xxxxxxx>
Reported-by: Piotr Zakowski <piotr.zakowski@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-i2c/20240213120553.7b0ab120@endymion.delvare/
Fixes: 315cd67c9453 ("i2c: i801: Add Block Write-Block Read Process Call support")
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 3159ffbb77a2..9a4e9bf304c2 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -500,11 +500,10 @@ static int i801_block_transaction_by_block(struct i801_priv *priv,
/* Set block buffer mode */
outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv));
- inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
-
if (read_write == I2C_SMBUS_WRITE) {
len = data->block[0];
outb_p(len, SMBHSTDAT0(priv));
+ inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
for (i = 0; i < len; i++)
outb_p(data->block[i+1], SMBBLKDAT(priv));
}
@@ -520,6 +519,7 @@ static int i801_block_transaction_by_block(struct i801_priv *priv,
return -EPROTO;
data->block[0] = len;
+ inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
for (i = 0; i < len; i++)
data->block[i + 1] = inb_p(SMBBLKDAT(priv));
}
