From 914a7b3563b8fb92f976619bbd0fa3a4a708baae Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: Mon, 17 Aug 2020 14:19:30 +0200
Subject: [PATCH] i2c: rcar: in slave mode, clear NACK earlier
Git-commit: 914a7b3563b8fb92f976619bbd0fa3a4a708baae
Patch-mainline: v5.9-rc3
References: git-fixes

Currently, a NACK in slave mode is set/cleared when SCL is held low by
the IP core right before the bit is about to be pushed out. This is too
late for clearing and then a NACK from the previous byte is still used
for the current one. Now, let's clear the NACK right after we detected
the STOP condition following the NACK.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/i2c/busses/i2c-rcar.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 9e883474db8c..c7c543483b08 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -590,6 +590,7 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
 	/* master sent stop */
 	if (ssr_filtered & SSR) {
 		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
+		rcar_i2c_write(priv, ICSCR, SIE | SDBS); /* clear our NACK */
 		rcar_i2c_write(priv, ICSIER, SAR);
 		rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
 	}
-- 
2.16.4