Rockbox mail archive
Subject: Re: Cowon D2 EABI
On 14/06/2010 22:08, pouly amaury wrote:
> I have a D2 (gevaerts's one) so I could investigate. Unfortunately I
> don't know anything about the port. Could you give me some insights of
> it or tell where you think the problem could be (you talked about a
> bit-banging issue). Perhaps I would be able to figure out what is wrong.
I had a look at the code generated by GCC 4.4.4 and compared it to the
previous version. As I suspected, the new compiler seems to optimise
away most of the delay_loop() in i2c-telechips.c, but unfortunately the
timing of this is critical for correct I2C reads/writes. That explains
why some drivers that use the PMU chip no longer work reliably.
To fix this I need to find a way for the new compiler to generate the
same code as the old version, or simply to find a new way of writing
this loop that generates the same, working, code on both compilers.
Not necessarily a simple task :/
Received on 2010-06-14
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