[ECOS] Problem found with flash driver

[Retallack, Mark]

After reading the flash.h file in more detail, it suggests placing
platform stuff in the correct file and not modifying the flash.h file. I
don't think this is a problem on all platforms so it does not make sence
to do a generic interrupt disable, so I have added it to the
mpc8xx/current/include/var_cache.h file instead. I placed it here and
not in the hal_cache.h because I don't know if it is a PowerPC issue or
just an MPC8xx issue. 

I have attached the patch.

-----Original Message-----
From: Neundorf, Alexander [mailto:Alexander.Neundorf@jenoptik.com] 
Sent: 02 March 2006 11:08
To: Retallack, Mark; ecos-discuss@ecos.sourceware.org
Subject: AW: [ECOS] Problem found with flash driver


Hi,

> Von: ecos-discuss-owner@ecos.sourceware.org
> 
> Hello everyone, I think I have found a minor problem with the io layer

> of the flash driver and before I continue with my fix, I just thought 
> that I would ask if anyone else has seen it.
> 
> I am using JFFS2 over a flash bank that I am not running code from, so

> interrupts can be enabled during flash access. The processor is an 
> MPC850.
> 
> With the virgin eCos flash.c code (from CVS), the system
> crashes with a
> random memory corruption, I have tracked it down to a context switch
> within the flash_program function in flash.c. After looking 
> through the
> file and the eCos mailing list I found that the HAL_FLASH_CACHES_OFF
> define states that interrupts must be disabled. 

I had also crashes when interrupts occured during flash_program(). But
since we don't write often on the flash, I simply disabled interrupts
when calling flash_program(). This is not optimal, but was good enough
for our purpose.
 
> After modding the code to disable interrupts before flushing and 
> disabling the cache, the system works correctly with no problems.

Sounds good :-)
There is also a different flash branch, maybe this is fixed there, I
don't know.
 
> I have not created a patch because the HAL_FLASH_CACHES_OFF define in 
> flash.h looks very generic and I cannot test the mod. But this is what

> I have done:

Can you please send it as a patch ?

Bye
Alex
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