This is a note to let you know that I've just added the patch titled i2c: rcar: slave: only send STOP event when we have been addressed to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: i2c-rcar-slave-only-send-stop-event-when-we-have-bee.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit a9bc22e5aa989485bcee0e828ecc07ec44d3844c Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Date: Mon Jun 29 17:38:07 2020 +0200 i2c: rcar: slave: only send STOP event when we have been addressed [ Upstream commit 314139f9f0abdba61ed9a8463bbcb0bf900ac5a2 ] When the SSR interrupt is activated, it will detect every STOP condition on the bus, not only the ones after we have been addressed. So, enable this interrupt only after we have been addressed, and disable it otherwise. Fixes: de20d1857dd6 ("i2c: rcar: add slave support") Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 93b8069041bb1..4231673435e7b 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -527,13 +527,14 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR); } - rcar_i2c_write(priv, ICSSR, ~SAR & 0xff); + /* Clear SSR, too, because of old STOPs to other clients than us */ + rcar_i2c_write(priv, ICSSR, ~(SAR | SSR) & 0xff); } /* master sent stop */ if (ssr_filtered & SSR) { i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value); - rcar_i2c_write(priv, ICSIER, SAR | SSR); + rcar_i2c_write(priv, ICSIER, SAR); rcar_i2c_write(priv, ICSSR, ~SSR & 0xff); } @@ -762,7 +763,7 @@ static int rcar_reg_slave(struct i2c_client *slave) priv->slave = slave; rcar_i2c_write(priv, ICSAR, slave->addr); rcar_i2c_write(priv, ICSSR, 0); - rcar_i2c_write(priv, ICSIER, SAR | SSR); + rcar_i2c_write(priv, ICSIER, SAR); rcar_i2c_write(priv, ICSCR, SIE | SDBS); return 0;