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From: Michael Jones <michael.jones@matrix-vision.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] I2C: OMAP: spurious i2c probe addresses
Date: Wed, 25 May 2011 17:38:08 +0200	[thread overview]
Message-ID: <4DDD2260.9000300@matrix-vision.de> (raw)

While running v2011.06-rc1, I noticed some new behavior on my OMAP3 i2c
bus.  I tracked it to commit 0e57968a215d1b, "I2C: OMAP: detect more
devices when probing an i2c bus".  It detects more devices indeed, such
as some that don't even exist. Even better than that, it detects
different devices every time.  It looks like just false positives, the
existent devices seem to always be found among the ghost devices.

Here's the behavior I see:
--------------------------
# i2c probe
Valid chip addresses: 05 18 30 49 50 51 5E 7A
# i2c probe
Valid chip addresses: 02 06 0B 18 1D 24 25 30 35 50 51 57 5D 6F 7C
# i2c probe
Valid chip addresses: 18 2E 30 33 35 50 51 62 6F
# i2c probe
Valid chip addresses: 18 1B 1F 2D 30 46 50 51 5C 5D
# i2c probe
Valid chip addresses: 0A 18 21 26 2B 30 32 50 51 60 66 69 6D 79
# i2c probe
Valid chip addresses: 08 09 18 1B 30 50 51 5E 6C


Here's what it looks like after reverting the commit:
------------------------------------------
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51
# i2c probe
Valid chip addresses: 18 30 50 51


-Michael

MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler
Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner

             reply	other threads:[~2011-05-25 15:38 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-25 15:38 Michael Jones [this message]
2011-05-26  7:03 ` [U-Boot] I2C: OMAP: spurious i2c probe addresses Michael Jones
2011-05-26  7:14   ` Heiko Schocher
2011-05-26  7:25   ` Andre Schwarz
2011-05-26  9:23   ` Nick Thompson
2011-05-26 11:38     ` Michael Jones
2011-05-26 12:35       ` Nick Thompson

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