From: Wolfram Sang <wsa@the-dreams.de>
To: linux-i2c@vger.kernel.org
Cc: linux-sh@vger.kernel.org, Magnus Damm <magnus.damm@gmail.com>,
Simon Horman <horms@verge.net.au>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Wolfram Sang <wsa@the-dreams.de>,
Kuninori Morimoto <kuninori.morimoto.gx@gmail.com>,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: [PATCH v3 07/11] i2c: rcar: don't issue stop when HW does it automatically
Date: Thu, 19 Nov 2015 15:56:47 +0000 [thread overview]
Message-ID: <1447948611-2615-8-git-send-email-wsa@the-dreams.de> (raw)
In-Reply-To: <1447948611-2615-1-git-send-email-wsa@the-dreams.de>
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
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 <wsa+renesas@sang-engineering.com>
---
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 d91acc11631554..87fccf20fc4c34 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;
--
2.1.4
next prev parent reply other threads:[~2015-11-19 15:56 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-19 15:56 [PATCH v3 00/11] i2c: rcar: tackle race conditions in the driver Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 01/11] i2c: rcar: make sure clocks are on when doing clock calculation Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 02/11] i2c: rcar: rework hw init Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 03/11] i2c: rcar: remove unused IOERROR state Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 04/11] i2c: rcar: remove spinlock Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 05/11] i2c: rcar: refactor setup of a msg Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 06/11] i2c: rcar: init new messages in irq Wolfram Sang
2015-11-19 15:56 ` Wolfram Sang [this message]
2015-11-19 15:56 ` [PATCH v3 08/11] i2c: rcar: check master irqs before slave irqs Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 09/11] i2c: rcar: revoke START request early Wolfram Sang
2016-03-31 21:02 ` Sergei Shtylyov
2016-03-31 22:48 ` Wolfram Sang
2016-04-01 19:55 ` Sergei Shtylyov
2016-04-01 20:14 ` Wolfram Sang
2016-04-01 23:05 ` Sergei Shtylyov
2016-04-02 7:27 ` Wolfram Sang
2016-04-02 12:51 ` Sergei Shtylyov
2016-04-03 8:25 ` Wolfram Sang
2016-04-03 13:35 ` Sergei Shtylyov
2016-04-03 13:47 ` Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 10/11] i2c: rcar: clean up after refactoring Wolfram Sang
2015-11-19 15:56 ` [PATCH v3 11/11] i2c: rcar: handle difference in setting up non-first message Wolfram Sang
2015-11-19 16:01 ` [PATCH v3 00/11] i2c: rcar: tackle race conditions in the driver Laurent Pinchart
2015-11-30 13:27 ` Wolfram Sang
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