On Thu, Jan 07, 2010 at 03:19:15PM -0500, Jean-Hugues Deschenes wrote: > > On Mon, Dec 15, 2008 at 03:31:55AM +0100, andrzej zaborowski wrote: > > >/ 2008/12/12 Edgar E. Iglesias <addr...@hidden>:/ > > >/ > I'm having problems with machine that uses a NAND_MFR_STMICRO 0xf1,/ > > >/ > recent Linux versions cannot properly read from the flash./ > > >/ >/ > > >/ > Turns out that Linux MTD recently learned howto do randomly accessed > > >reads/ > > >/ > from NAND flashes. QEMU has problemns emulating these./ > > >/ >/ > > >/ > This patch fixes the problem for me but I've only tested on one flash/ > > >/ > model and only with Linux. I'd appreciate help with testing more > > >machines/ > > >/ > with NANDs and ofcourse any comments people may have on the patch./ > > >/ >/ > > >/ > Thanks/ > > >/ >/ > > >/ > commit 68a19f4348b12f85bd5fbfd8cf7b19033e1fd784/ > > >/ > Author: Edgar E. Iglesias <addr...@hidden>/ > > >/ > Date: Fri Dec 12 12:48:58 2008 +0100/ > > >/ >/ > > >/ > NAND: Correct random data reads./ > > >/ >/ > > >/ > Random reading depends on having the last row/page latched and not > > >beeing/ > > >/ > clobbered between read and any following random reads./ > > >/ >/ > > >/ > Also, s->iolen must be updated when loading the io/data register > > >with / > > >/ > randomly/ > > >/ > accessed flash data./ > > >/ >/ > > >/ > Signed-off-by: Edgar E. Iglesias <addr...@hidden>/ > > >/ > + unsigned int offset;/
... > > >/ Won't that break sequential reading? I think the other modifications/ > > > > I found specs for a flash with sequential page-crossing reads. My > > code does not handle that but neither does current svn AFAICT. The > > masking is wrong, we'll always end up at page 1. > > > > >/ should also be conditional on the command being RANDOMREAD./ > > >/ / > > >/ BTW, do you happen to know what the difference is between RANDOMREAD2/ > > >/ and NOSERIALREAD2? I basically added those commands because various/ > > > > AFAIK noserial reads are for preparing copyback writes. Random reads are > > for random access within the page register. > > > > I'll try to fix and test the page-crossing seqreads. > > > > Thanks alot for the comments. > Hi, > > I'm just wondering what is the status of this patch; It has definitely > solved one of my problems, where a NAND flash controller I'm emulating sends > random read commands to an emulated large page device. Hi, I forgot about this one.. It's in one of my trees, I'll try to find it & repost and see if there is more feedback. My main concern was that I only had linux guests to test with. Cheers
