From: Jan Weitzel <j.weitzel-guT5V/WYfQezQB+pC5nmwQ@public.gmane.org>
To: linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
b-cousson-l0cyMroinI0@public.gmane.org,
andy.green-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org
Cc: andy-/Zus8d0mwwtBDgjK7y7TUQ@public.gmane.org,
tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org,
peter.maydell-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org,
khilman-l0cyMroinI0@public.gmane.org,
ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Jan Weitzel <j.weitzel-guT5V/WYfQezQB+pC5nmwQ@public.gmane.org>
Subject: [PATCH] ARM: OMAP2+ i2c NACK without STP
Date: Tue, 14 Jun 2011 12:54:13 +0200 [thread overview]
Message-ID: <1308048853-21911-1-git-send-email-j.weitzel@phytec.de> (raw)
In-Reply-To: <20110614102409.GN3352-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
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)
Fixes also booting on 2430sdp.
Signed-off-by: Jan Weitzel <j.weitzel-guT5V/WYfQezQB+pC5nmwQ@public.gmane.org>
Acked-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
---
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 parent reply other threads:[~2011-06-14 10:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110614102409.GN3352@atomide.com>
[not found] ` <20110614102409.GN3352-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
2011-06-14 10:54 ` Jan Weitzel [this message]
2011-12-27 14:48 ` [PATCH] ARM: OMAP2+ i2c NACK without STP T Krishnamoorthy, Balaji
[not found] ` <CANrkHUZ530H+0+YKy2QJPFbwUQ1zqD=OaSrF6ByTbpx6eU421Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-04 0:07 ` Kevin Hilman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1308048853-21911-1-git-send-email-j.weitzel@phytec.de \
--to=j.weitzel-gut5v/wyfqezqb+pc5nmwq@public.gmane.org \
--cc=andy-/Zus8d0mwwtBDgjK7y7TUQ@public.gmane.org \
--cc=andy.green-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
--cc=b-cousson-l0cyMroinI0@public.gmane.org \
--cc=ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org \
--cc=khilman-l0cyMroinI0@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
--cc=peter.maydell-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org \
--cc=tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).