[PATCH] i2c: i801: Fix a refactoring that broke a touchpad on Lenovo P1

From: Maxim Levitsky
Date: Thu Mar 21 2024 - 10:19:53 EST


Commit 857cc04cdf50 ("i2c: i801: Add helper i801_get_block_len")
introduced a slight functional change: the status variable is now
overwritten with the length of an SMBUS tranasaction,
even in case of success.

This breaks the touchpad on at least my Lenovo P1:

rmi4_physical rmi4-00: Read PDT entry at 0x00e9 failed, code: -6.
rmi4_physical rmi4-00: RMI initial reset failed! Continuing in spite of this.
rmi4_physical rmi4-00: Read PDT entry at 0x00e9 failed, code: -6.
rmi4_physical rmi4-00: IRQ counting failed with code -6.

Fixes: 857cc04cdf50 ("i2c: i801: Add helper i801_get_block_len")

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-i801.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index a6861660cb8c..79870dd7a014 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -536,11 +536,12 @@ static int i801_block_transaction_by_block(struct i801_priv *priv,

if (read_write == I2C_SMBUS_READ ||
command == I2C_SMBUS_BLOCK_PROC_CALL) {
- status = i801_get_block_len(priv);
- if (status < 0)
+ len = i801_get_block_len(priv);
+ if (len < 0) {
+ status = len;
goto out;
+ }

- len = status;
data->block[0] = len;
inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */
for (i = 0; i < len; i++)
--
2.40.1