diff options
| author | Quan Nguyen <quan@os.amperecomputing.com> | 2023-07-26 15:00:00 +0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-23 17:52:31 +0200 |
| commit | 52114963307e6e3afa22b07da5f54a682ea1b1a5 (patch) | |
| tree | 6ee80777cea2a547a12128dd70bc38b0bae42cff | |
| parent | ceb9ba8e30833a4823e2dc73f80ebcdf2498d01a (diff) | |
| download | linux-52114963307e6e3afa22b07da5f54a682ea1b1a5.tar.gz | |
i2c: designware: Correct length byte validation logic
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@vger.kernel.org
Signed-off-by: Tam Nguyen <tamnguyenchi@os.amperecomputing.com>
Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Link: https://lore.kernel.org/r/20230726080001.337353-2-tamnguyenchi@os.amperecomputing.com
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index dc3c5a15a95b..553ce16f0666 100644 --- 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; |