Re: [PATCH] Bugfixes for i2c-cpm.c

Laurent Pinchart
2008-07-01T13:26:11Z

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On Friday 27 June 2008, Jochen Friedrich wrote:
> Hi Laurent,
>
> >> Bugfixes to the i2c-cpm driver
> >>
> >> - enable correct interrupts (I2CER_TXE instead of I2CER_BUSY)
> >> - replace forgotten iic with i2c
> >> - fix typo (devided)
> >> - prefix debug-output on init with 0x and add frequency
> >>
> >> Signed-off-by: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
> >
> > Tested on a MPC8247 board. I have experienced I2C issues since migration
> > from ppc to powerpc. This patch seems to solve the problem.
>
> What kind of problems have this been? In normal operation there shouldn't be
> any I2CER_TXE interrupts being generated.

I2C devices would frequently (about once every 10 cold boots) be undetected by the kernel. I tried to investigate the issue by hooking up a scope to the I2C signals, but haven't been able to reproduce the problem once the probes were connected.

This might of course be a case of Murphy's law in action, but the problem disappeared after applying the patch.

--
Laurent Pinchart
CSE Semaphore Belgium

Chaussee de Bruxelles, 732A
B-1410 Waterloo
Belgium

T +32 (2) 387 42 59
F +32 (2) 387 42 75

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