From: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>
commit 49d4db3953cb9004ff94efc0c176e026c820af5a upstream.
Commit 0daede80f870 ("i2c: designware: Convert driver to using regmap API")
changes the logic to validate the whole 32-bit return value of
DW_IC_DATA_CMD register instead of 8-bit LSB without reason.
Later, commit f53f15ba5a85 ("i2c: designware: Get right data length"),
introduced partial fix but not enough because the "tmp > 0" still test
tmp as 32-bit value and is wrong in case the IC_DATA_CMD[11] is set.
Revert the logic to just before commit 0daede80f870
("i2c: designware: Convert driver to using regmap API").
Fixes: f53f15ba5a85 ("i2c: designware: Get right data length")
Fixes: 0daede80f870 ("i2c: designware: Convert driver to using regmap API")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Tam Nguyen <tamnguyenchi@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>
Acked-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230726080001.337353-2-tamnguyenchi@xxxxxxxxxxxxxxxxxxxxxx
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-master.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -525,9 +525,10 @@ i2c_dw_read(struct dw_i2c_dev *dev)
u32 flags = msgs[dev->msg_read_idx].flags;
regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
+ tmp &= DW_IC_DATA_CMD_DAT;
/* Ensure length byte is a valid value */
if (flags & I2C_M_RECV_LEN &&
- (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
+ tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
len = i2c_dw_recv_len(dev, tmp);
}
*buf++ = tmp;
