From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wolfram Sang , Wolfram Sang , Fabrizio Castro , Biju Das Subject: [PATCH 4.4 21/37] i2c: rcar: dont issue stop when HW does it automatically Date: Tue, 5 Jun 2018 19:01:26 +0200 Message-Id: <20180605170110.133552831@linuxfoundation.org> In-Reply-To: <20180605170108.884872354@linuxfoundation.org> References: <20180605170108.884872354@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wolfram Sang commit d89667b14f9d13b684287f6189ca209af5feee43 upstream. 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 Signed-off-by: Wolfram Sang Signed-off-by: Fabrizio Castro Reviewed-by: Biju Das Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-rcar.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -455,8 +455,8 @@ static irqreturn_t rcar_i2c_irq(int irq, /* 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;