[U-Boot] [PATCH 1/1] NAND Re: mtdparts fails with NAND >= 4GB - Second try

[Aaron Williams]

On Thursday, February 10, 2011 07:24:54 pm Aaron Williams wrote:
> On Thursday, February 10, 2011 07:08:01 am Andrew Dyer wrote:
> > On Thu, Feb 10, 2011 at 00:28, Aaron Williams
> > 
> > <Aaron.Williams at caviumnetworks.com> wrote:
> > >> I would suggest to make sure any caching/prefetching stuff is off,
> > >> hardware is doing one flash bus access per CPU read/write.
> > >> 
> > >> In cmdset_amd_read_jedec_ids() after this line:
> > >> 
> > >> manuId = flash_read_uchar (info, FLASH_OFFSET_MANUFACTURER_ID);
> > >> 
> > >> add something like
> > >> 
> > >> printf("test manf id word = %04x\n", *(volatile uint16_t
> > >> *)0x1f400000); printf("test device id word = %04x\n", *(volatile
> > >> uint16_t
> > >> *)0x1f400002); printf("test device id word = %04x\n", *(volatile
> > >> uint16_t *)0x1f40001c); printf("test device id word = %04x\n",
> > >> *(volatile uint16_t *)0x1f40001e);
> > >> 
> > >> and see what you get.
> > > 
> > > fwc addr 1f400000 cmd f0 f0f0 16bit x 8 bit
> > > flash_write16: address: 1f400000, value: 0xf0f0
> > > fwc addr 1f401554 cmd aa aaaa 16bit x 8 bit
> > > flash_write16: address: 1f401554, value: 0xaaaa
> > > fwc addr 1f400aaa cmd 55 5555 16bit x 8 bit
> > > flash_write16: address: 1f400aaa, value: 0x5555
> > > fwc addr 1f401554 cmd 90 9090 16bit x 8 bit
> > > flash_write16: address: 1f401554, value: 0x9090
> > > flash_read8: address: 1f400001, value: 0x0
> > > test manf id word = 1000
> > > test device id word = 013f
> > > test device id word = da6c
> > > test device id word = 2926
> > 
> > looks like garbage :-(  What's in the flash at those addresses?  Maybe
> > something is happening to mess up the unlock sequence and you're
> > reading the memory data instead of the device codes.
> > 
> > It's odd that earlier in the sequence when the CFI query data is read
> > the byte data is mirrored across both bytes of the response, here the
> > two bytes are different.
> 
> I received an email back from Spansion about this problem. They suggested
> that instead of the following:
> 
> fwc addr 1f401554 cmd aa aaaa 16bit x 8 bit
> flash_write16: Wrote 0xaaaa to address 1f401554
> funlock writing 0xaa to address 0x555
> fwc addr 1f400aaa cmd 55 5555 16bit x 8 bit
> flash_write16: Wrote 0x5555 to address 1f400aaa
> fwc addr 1f401554 cmd 90 9090 16bit x 8 bit
> flash_write16: Wrote 0x9090 to address 1f401554
> 
> to instead do the following:
> write 0xAA to 0x1F400AAA
> write 0x55 to 0x1F400555
> write 0x90 to 0x1F400AAA
> 
> read 0x1F400001 returns 0x01
> read 0x1F400003 returns 0x7e
> 
> This looks correct.
> 
> I found two things I need to do to work around the problem. First, in
> flash_write_cmd I use info->chipwidth instead of info->portwidth for the
> write commands, and second, in __flash_detect_cfi I don't modify the
> address in compatibility mode. This works. If either of those steps are
> left out then reading the manufacturer ID fails.
> 
> -Aaron

It looks like I spoke too soon. It fixes the manufacturer problem but 
everything else is now broken.

-Aaron