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
