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 Kaneko <ykaneko0929@gmail.com>,
Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: [PATCH 6/9] i2c: rcar: don't issue stop when HW does it automatically
Date: Thu, 03 Sep 2015 20:20:10 +0000 [thread overview]
Message-ID: <1441311613-2681-7-git-send-email-wsa@the-dreams.de> (raw)
In-Reply-To: <1441311613-2681-1-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 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
next prev parent reply other threads:[~2015-09-03 20:20 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 20:20 [PATCH 0/9] i2c: rcar: tackle race conditions in the driver Wolfram Sang
2015-09-03 20:20 ` [PATCH 1/9] i2c: rcar: rework hw init Wolfram Sang
2015-09-03 20:20 ` [PATCH 2/9] i2c: rcar: remove unused IOERROR state Wolfram Sang
2015-09-03 20:20 ` Wolfram Sang [this message]
[not found] ` <1441311613-2681-1-git-send-email-wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
2015-09-03 20:20 ` [PATCH 3/9] i2c: rcar: remove spinlock Wolfram Sang
2015-09-03 20:20 ` [PATCH 4/9] i2c: rcar: refactor setup of a msg Wolfram Sang
2015-09-03 20:20 ` [PATCH 5/9] i2c: rcar: init new messages in irq Wolfram Sang
2015-10-21 23:10 ` Laurent Pinchart
2015-10-22 11:05 ` Wolfram Sang
2015-10-22 11:12 ` Laurent Pinchart
2015-10-23 8:06 ` Wolfram Sang
[not found] ` <2048622.tkxROUAu7P@avalon>
2015-10-23 9:45 ` Wolfram Sang
2015-10-23 10:28 ` Laurent Pinchart
2015-10-23 12:14 ` Wolfram Sang
2015-10-23 13:14 ` Laurent Pinchart
2015-10-25 15:53 ` Wolfram Sang
2015-10-29 19:23 ` Wolfram Sang
2015-10-23 10:04 ` Geert Uytterhoeven
2015-10-23 10:07 ` Wolfram Sang
2015-09-03 20:20 ` [PATCH 7/9] i2c: rcar: check master irqs before slave irqs Wolfram Sang
2015-09-03 20:20 ` [PATCH 8/9] i2c: rcar: revoke START request early Wolfram Sang
2015-09-03 20:20 ` [PATCH 9/9] i2c: rcar: clean up after refactoring Wolfram Sang
2015-09-03 20:35 ` [PATCH 0/9] i2c: rcar: tackle race conditions in the driver Laurent Pinchart
2015-09-03 20:40 ` Wolfram Sang
2015-09-03 20:47 ` Laurent Pinchart
2015-09-03 20:55 ` Wolfram Sang
2015-09-04 4:33 ` Magnus Damm
2015-09-05 7:31 ` Wolfram Sang
2015-09-07 16:04 ` Magnus Damm
[not found] ` <CANqRtoRs=f=07B=HSLCVg5G4rnhxj6Heod+spYwxHiKFLZqFWg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-08 10:53 ` Wolfram Sang
2015-09-09 5:08 ` Magnus Damm
2015-09-09 8:54 ` Wolfram Sang
2015-10-09 21:34 ` Wolfram Sang
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