Hi Peter,
On Thu, Oct 11, 2012 at 15:05:43, Peter Meerwald wrote:
> I'm getting the kernel log messages early in the bootup sequence (kernel
> 3.6.1 mainline)
> [ 0.121337] GPMC revision 5.0
> [ 0.121582] gpmc: irq-20 could not claim: err -22
This issue has been present for quite some time, now as
certain gpmc patches got merged recently (during the
ongoing merge window), this should be gone.
> NAND still works since it is operated in NAND_OMAP_PREFETCH_POLLED mode;
> however, I'd like to try NAND_OMAP_PREFETCH_IRQ to see if it brings any
> performance gains
I vaguely remember that once while checking irq mode (not mainline,
on am335x-evm), speed was less compared to default, so I doubt whether
you get any performance gains, anyway it would be good to know
performance results in your case.
> just passing NAND_OMAP_PREFETCH_IRQ via gmpc_nand_init() hangs the kernel
> (I guess since the request_irq() failed earlier)
With mainline HEAD, you should be able to use irq.
> another question is dev_ready which also seems to depend on IRQ also
Now it is no more.
> can you make any recommendation w.r.t NAND performance on OMAP?
Once DMA was checked, but found it slower than other two, not sure
whether I was doing anything wrong. Right now don't have any
suggestions, if I come across any will let you know.
Regards
Afzal
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