From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Date: Thu, 03 Sep 2015 20:20:10 +0000 Subject: [PATCH 6/9] i2c: rcar: don't issue stop when HW does it automatically Message-Id: <1441311613-2681-7-git-send-email-wsa@the-dreams.de> List-Id: References: <1441311613-2681-1-git-send-email-wsa@the-dreams.de> In-Reply-To: <1441311613-2681-1-git-send-email-wsa@the-dreams.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-i2c@vger.kernel.org Cc: linux-sh@vger.kernel.org, Magnus Damm , Simon Horman , Laurent Pinchart , Geert Uytterhoeven , Wolfram Sang , Kuninori Morimoto , Yoshihiro Kaneko , Sergei Shtylyov From: Wolfram Sang The manual says (55.4.8.6) that HW does automatically send STOP after NACK was received. My measuerments confirm that. Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-rcar.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 36c79301044b71..dcf9fc77cec7c4 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -458,8 +458,8 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) /* Nack */ if (msr & MNR) { - /* go to stop phase */ - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + /* HW automatically sends STOP after received NACK */ + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP); rcar_i2c_flags_set(priv, ID_NACK); goto out; -- 2.1.4