From: Jan Weitzel <j.weitzel@phytec.de>
To: linux-omap@vger.kernel.org, b-cousson@ti.com,
andy.green@linaro.org, patches@linaro.org
Cc: andy@warmcat.com, tony@atomide.com, peter.maydell@linaro.org,
khilman@ti.com, Jan Weitzel <j.weitzel@phytec.de>
Subject: [RFC] ARM: OMAP2+ i2c NACK without STP
Date: Tue, 14 Jun 2011 12:05:59 +0200 [thread overview]
Message-ID: <1308045959-24269-1-git-send-email-j.weitzel@phytec.de> (raw)
In-Reply-To: <87oc30t81u.fsf@ti.com>
On OMAP4 OMAP_I2C_STAT_NACK is causing a timeout on the next access.
The isr cleans all flags in OMAP_I2C_CON_REG by setting OMAP_I2C_CON_STP
OMAP_I2C_CON_STP is also set in omap_i2c_xfer_msg on the last message.
According to the TI TSR the sequence for OMAP_I2C_STAT_NACK and
OMAP_I2C_STAT_AL are nearly the same.
Removing the OMAP_I2C_CON_STP part in the isr fix the problem.
Tested on OMAP4430 and OMAP3530 (here NACK was not a problem)
Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
---
drivers/i2c/busses/i2c-omap.c | 6 ++----
1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 58a58c7..670f2a2 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -836,11 +836,9 @@ complete:
~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
- if (stat & OMAP_I2C_STAT_NACK) {
+ if (stat & OMAP_I2C_STAT_NACK)
err |= OMAP_I2C_STAT_NACK;
- omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
- OMAP_I2C_CON_STP);
- }
+
if (stat & OMAP_I2C_STAT_AL) {
dev_err(dev->dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL;
--
1.7.0.4
next prev parent reply other threads:[~2011-06-14 10:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-21 11:47 [PATCH] ARM: omap4: i2c reset regs postidle Jan Weitzel
2011-04-21 12:13 ` Andy Green
2011-05-16 7:56 ` Jan Weitzel
2011-05-16 8:13 ` Andy Green
2011-05-16 9:18 ` [PATCH v2] " Jan Weitzel
2011-05-16 17:16 ` Cousson, Benoit
2011-05-17 9:26 ` [PATCH v3] " Jan Weitzel
2011-05-17 14:12 ` Kevin Hilman
2011-05-18 13:07 ` Jan Weitzel
2011-05-18 14:09 ` Kevin Hilman
2011-06-14 10:05 ` Jan Weitzel [this message]
2011-06-14 10:24 ` [RFC] ARM: OMAP2+ i2c NACK without STP Tony Lindgren
[not found] ` <20110614102409.GN3352-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
2011-06-14 10:54 ` [PATCH] " Jan Weitzel
2011-12-27 14:48 ` T Krishnamoorthy, Balaji
[not found] ` <CANrkHUZ530H+0+YKy2QJPFbwUQ1zqD=OaSrF6ByTbpx6eU421Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-04 0:07 ` Kevin Hilman
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