From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabrizio Castro Subject: [PATCH 1/3] i2c: rcar: don't issue stop when HW does it automatically Date: Wed, 30 May 2018 11:07:11 +0100 Message-ID: <1527674833-13122-2-git-send-email-fabrizio.castro@bp.renesas.com> References: <1527674833-13122-1-git-send-email-fabrizio.castro@bp.renesas.com> Return-path: In-Reply-To: <1527674833-13122-1-git-send-email-fabrizio.castro@bp.renesas.com> Sender: stable-owner@vger.kernel.org To: Greg Kroah-Hartman Cc: Wolfram Sang , Wolfram Sang , linux-i2c@vger.kernel.org, Chris Paterson , Biju Das , Fabrizio Castro , stable@vger.kernel.org, Ben Hutchings List-Id: linux-i2c@vger.kernel.org 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 [fabrizio: cherry-pick to 4.4] Signed-off-by: Fabrizio Castro Reviewed-by: Biju Das --- 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 44662e2..6f23b97 100644 --- 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, 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; -- 2.7.4