Re: JFFS2+NAND problem in 2.6.13-at91

[Aras Vaichas <arasv@magellan-technology.com>]

Aras Vaichas wrote:
> Aras Vaichas wrote:
> 
>>Hi,
>>
>>I was previously using 2.6.12-rc1, AT91 with JFFS2 on NAND and I had no
>>problems whatsoever with using JFFS2 on NAND.
>>
>>I recently upgraded to 2.6.13 and now JFFS2 on NAND seems a little broken ...

Jian Zhang wrote:

> i turn off debugging information( only MTD_DEBUG_LEVEL3) in nand_read_ecc( ),
> nand_write_ecc( ),nand_read_oob( ),nand_write_oob( ) which contained in
nand_base.c
> seperately. eventually,i found that it works well except turning off debugging
> info in nand_read_oob( ).so i insert  3us delay in this routine.

Thanks for the hint, I've got my NAND working again.

I did a diff between the nand_base.c version shipped with 2.6.13 (v1.147) and
2.6.12-rc1 (v1.138) and noticed that a delay loop had been moved further down
the code, I moved this delay back to where it was in v1.138 and it is now
working again. i assume that there was a probably a good reason to move this
delay in the first place though and I don't wish to break anything else ...

e.g.

--- drivers/mtd/nand/nand_base.c.orig   2005-09-14 13:28:07.000000000 +1000
+++ drivers/mtd/nand/nand_base.c        2005-09-14 13:37:59.000000000 +1000
@@ -1410,6 +1410,18 @@
                this->read_buf(mtd, &buf[i], thislen);
                i += thislen;

+
+               /* Apply delay or wait for ready/busy pin
+                * Do this before the AUTOINCR check, so no problems
+                * arise if a chip which does auto increment
+                * is marked as NOAUTOINCR by the board driver.
+                */
+               if (!this->dev_ready)
+                       udelay (this->chip_delay);
+               else
+                       nand_wait_ready(mtd);
+
+
                /* Read more ? */
                if (i < len) {
                        page++;
@@ -1421,16 +1433,6 @@
                                this->select_chip(mtd, -1);
                                this->select_chip(mtd, chipnr);
                        }
-
-                       /* Apply delay or wait for ready/busy pin
-                        * Do this before the AUTOINCR check, so no problems
-                        * arise if a chip which does auto increment
-                        * is marked as NOAUTOINCR by the board driver.
-                        */
-                       if (!this->dev_ready)
-                               udelay (this->chip_delay);
-                       else
-                               nand_wait_ready(mtd);

                        /* Check, if the chip supports auto page increment
                         * or if we have hit a block boundary.

Tom, did you want to check this? Should I submit a patch?

regards,

Aras Vaichas