From 6d133b31580a90e24fe95292a3e55aabe0fcc2da Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Wed, 26 Oct 2022 08:49:19 +0100 Subject: [PATCH] i2c: microchip: fix erroneous late ack send 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 Fixes: 0dc0d1e094 ("i2c: Add Microchip PolarFire SoC I2C driver") Signed-off-by: Conor Dooley Reviewed-by: Padmarao Begari Reviewed-by: Heiko Schocher Removed Tag by hs: Fixes: 0190d48488 ("i2c: microchip: fix ack sending logic") --- drivers/i2c/i2c-microchip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-microchip.c b/drivers/i2c/i2c-microchip.c index 3a27459..d82b80f 100644 --- a/drivers/i2c/i2c-microchip.c +++ b/drivers/i2c/i2c-microchip.c @@ -224,7 +224,7 @@ static void mpfs_i2c_empty_rx(struct mpfs_i2c_bus *bus) bus->msg_len--; } - if (bus->msg_len == 0) { + if (bus->msg_len <= 1) { ctrl = readl(bus->base + MPFS_I2C_CTRL); ctrl &= ~CTRL_AA; writel(ctrl, bus->base + MPFS_I2C_CTRL); -- 2.7.4