[Fwd: mpc8xx, i2c read DB busy issue]

[Ankur Maheshwari <ankur_maheshwari@procsys.com>]

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From: Ankur Maheshwari <ankur_maheshwari@procsys.com>
To: linuxppc-embedded@ozlabs.org
Subject: mpc8xx, i2c read DB busy issue
Date: Fri, 26 Oct 2007 15:00:31 +0530
Message-ID: <4721B3B7.8070602@procsys.com>

Hi all,

I am trying to use mpc860 as i2c-SLAVE. Kernel, I am using is 
Linux-2.4.4, which I can't change due to some reasons.

I am able to do I2C read/write operations on mpc8xx-i2c slave only after 
re-insmoding my driver module (i2c-algo-8xx.c, and adapter layer drive, 
code I took form i2c-rpx/r360.c ).

The issue I am facing is when I insmod i2c-driver on fresh Linux boot, 
any i2c-mpc860 as slave read/write operation gives me busy status (which 
is for Rx BD not available) in Controller's i2c Event Registers. When I 
get busy status I have to do force_close() and re-init of bd, then only 
busy status goes off.

I tried calling cpm_iic_init(); twice while __init but with no change in 
busy status.

After some initial try, i2c slave write works but i2c read gives no data 
to the master. After re-insmoding driver, read/write works with some 
times (1 out of 15 times) i2c-read failing.

But still I can't understand why busy is coming....

Any help or suggestions are highly appreciated.

thanks,
Ankur Maheshwari