system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-30 00:10:51 +00:00
Code Issues Packages Projects Releases Wiki Activity

i2c: microchip-corei2c: fix erroneous late ack send

Browse source 
A late ack is currently being sent at the end of a transfer due to
incorrect logic in mchp_corei2c_empty_rx(). Currently the Assert Ack
bit is being written to the controller's control reg after the last
byte has been received, causing it to sent another byte with the ack.
Instead, the AA flag should be written to the control register when
the penultimate byte is read so it is sent out for the last byte.

Reported-by: Andreas Buerkler <andreas.buerkler@enclustra.com>
Fixes: 64a6f1c498 ("i2c: add support for microchip fpga i2c controllers")
Tested-by: Lewis Hanly <lewis.hanly@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
[wsa: fixed typos in commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Conor Dooley 2022-08-05 08:43:46 +01:00 committed by Wolfram Sang
parent 0a0b80a44c
commit dde61c4830
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/i2c/busses/i2c-microchip-corei2c.c
View file

@ -206,7 +206,7 @@ static void mchp_corei2c_empty_rx(struct mchp_corei2c_dev *idev)
idev->msg_len--;
}
if (idev->msg_len == 0) {
if (idev->msg_len <= 1) {
ctrl = readb(idev->base + CORE_I2C_CTRL);
ctrl &= ~CTRL_AA;
writeb(ctrl, idev->base + CORE_I2C_CTRL);