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Commit d074d5ff authored by Jean Delvare's avatar Jean Delvare Committed by Greg Kroah-Hartman
Browse files

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: default avatarJean Delvare <jdelvare@suse.de>
Reported-by: default avatarPiotr Zakowski <piotr.zakowski@intel.com>
Closes: https://lore.kernel.org/linux-i2c/20240213120553.7b0ab120@endymion.delvare/


Fixes: 315cd67c ("i2c: i801: Add Block Write-Block Read Process Call support")
Reviewed-by: default avatarAlexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 4de1489d

drivers/i2c/busses/i2c-i801.c

+2 −2
Original line number Diff line number Diff line
@@ -531,11 +531,10 @@ 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));

	}
@@ -551,6 +550,7 @@ 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));

	}