From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sauhun.de ([88.99.104.3]:60560 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814AbeD1UBI (ORCPT ); Sat, 28 Apr 2018 16:01:08 -0400 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Kuninori Morimoto , Wolfram Sang Subject: [PATCH] i2c: rcar: enhance comment to avoid regressions Date: Sat, 28 Apr 2018 22:01:02 +0200 Message-Id: <20180428200102.16498-1-wsa@the-dreams.de> Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: From: Wolfram Sang Give a clear testcase for people wishing to change this code. It is also a reminder for me if people ask about it. Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rcar.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index c6915b835396..9d8d5b91220f 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -542,6 +542,8 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) * If next received data is the _LAST_, go to STOP phase. Might be * overwritten by REP START when setting up a new msg. Not elegant * but the only stable sequence for REP START I have found so far. + * If you want to change this code, make sure sending one transfer with + * four messages (WR-RD-WR-RD) works! */ if (priv->pos + 1 >= msg->len) rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); -- 2.11.0