From: Jean Delvare Date: Wed, 14 Feb 2024 14:59:39 +0000 (+0100) Subject: i2c: i801: Fix block process call transactions X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c1c9d0f6f7f1dbf29db996bd8e166242843a5f21;p=linux.git i2c: i801: Fix block process call transactions 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 Reported-by: Piotr Zakowski 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 Signed-off-by: Andi Shyti --- diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 3932e8d96a171..2c36b36d7d516 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -498,11 +498,10 @@ 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, } 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)); }