2009/3/26 Jim Rayner : >> Out of interest, do you have CPUFREQ enabled? You might want to try >> disabling it, as it ends up doubling the speed we talk to NAND in a way >> that didn't happen with the 2.6.25 stuff. > > Many thanks, that appears to have done the trick, I've restored my root fs, > 0 retired blocks, 0 status errors Another thought: we (I) changed bootldr after the 2.6.29 kernel work so that it slows down access to the NAND, Samosa and other devices on nCS4, in order to compensate for the doubled bus speed in the new kernel. Were you running the latest bootldr, Jim? It sounds like this has just bumped variable latency IO for the CPLD address space up the priority chart even further, given what we discovered about Samosa timings the other week. I think there may be some design issues to think about: - are we currently trying to run NAND bus cycles too fast? This is moderately unlikely since we slowed it down hugely to make the minipug LCDs work over Samosa, unless Jim was running an old bootldr. - do we want to observe NAND_RNB in hardware (thus locking up the bus while the NAND gets its act together) or in software? I'm not even sure that this is an appropriate question to ask, but someone else may have a quick answer before I go and grub around in data sheets and kernel source. Chris -- Chris Jones - chris@martin-jones.com Martin-Jones Technology Ltd, makers of Solidlights 148 Catharine Street, Cambridge, CB1 3AR, UK Phone +44 (0) 1223 655611 Fax +44 (0) 870 112 3908 http://www.solidlights.co.uk/