Hi Gupta, On Wed, Oct 23, 2013 at 01:15:20PM +0000, Gupta, Pekon wrote: > Hi, > > > From: Ezequiel Garcia [mailto:ezequiel.garcia@xxxxxxxxxxxxxxxxxx] > [...] > > FWIW, I have a Beaglebone with a 16-bit bus NAND attached to it. > > > > Coincidentally, yesterday I was doing some tests as I'm ramping up the > > NAND and I found that weird double nand_scan_ident() call. > > The whole thing looks buggy to me, so I'm happy to help, review, test > > and patches to take care of this. > > > Yes, thanks .. that would be of great help.. > And may be your experience of Atmel drivers would help me here.. > It's not Atmel, but Marvell :-) > *Correct, should not be double calls to nand_scan_ident()..* > But there is a constrain in nand_base.c, that it does not allow ONFI > page reading in x16 mode.. So how to overcome that.. > > I see the similar implementation in your ATMEL driver, it does not use > NAND_BUSWIDTH_AUTO so how do you perform ONFI read > for x16 devices ? > drivers/mtd/nand/atmel_nand.c @@atmel_nand_probe() > /* here you move to x16 mode based on your DT or platform data */ > if (host->board.bus_width_16) /* 16-bit bus width */ > nand_chip->options |= NAND_BUSWIDTH_16; > /* And then you call nand_scan_ident */ > /* first scan to find the device and get the page size */ > if (nand_scan_ident(mtd, 1, NULL)) { > res = -ENXIO; > goto err_scan_ident; > } > > Wouldn't this fail, _unless_ your device is listed in nand_flash_id[] ? > because it would not be able to read ONFI params.. > Refer below commit.. > commit 0ce82b7f7b7373b16ecf7b5725e21e2975204500 > Author: Matthieu CASTET <matthieu.castet@xxxxxxxxxx> > AuthorDate: 2013-01-16 > > Not my driver, but I'm taking a look at it now. Not sure if I'll get into something here. > > > > I'm using some TI SDK with some ancient v3.2.x (with no git history!), > > but from this discussion it seems the issue is still present in > > mainline. > > > Aah sorry, then you might have some problem here in rebasing the > patches. But still if you can, thanks much .. > I'm currently trying mainline (just for this issue not for my product). I just need some time to prepare the bootargs and write a DT node for the NAND cape. Again, not sure if I'll make some progress, but I'll give it a shot :-) -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
