* Stefan Roese | 2008-07-15 10:46:33 [+0200]:
Hi Sebastian,
Hi Stefan,
On Monday 14 July 2008, Sebastian Siewior wrote:
This got broken by commits 93c56f212c [cfi_flash: support of long cmd in U-boot.]
That command seems to be access in a little endian way so wrappers are required.
Please explain why this is the case? Little endian wrappers on big endian machines for FLASH access? This sounds wrong to me.
Look at this snippet from flash_make_cmd (my case: big endian & CFG_WRITE_SWAPPED_DATA):
| for (i = info->portwidth; i > 0; i--){ | cword_offset = (info->portwidth-i)%info->chipwidth; | cp_offset = info->portwidth - i; | val = *((uchar*)&cmd + cword_offset); | cp[cp_offset] = (cword_offset >= sizeof(uint)) ? 0x00 : val; | } |
Now, 8bit access, 8bit bus: portwidth = 1, chipwidth = 1. I am only once in this for loop and I get the MSB byte of cmd which is 0x00 instead of the command which is never touched.
Long is the wrong type because it will behave differently on 64bit machnines in a way that is probably not expected. int should be enough.
Yes. I suggest that you move this long/int issue to a separate patch. It isn't related to this endian issue.
Right.
And to you main patch:
NAK. After applying this, CFI support on kilauea (PPC405EX with 1* Spansion S29GL512N, 16bit wide) breaks:
Is this big endian + CFG_WRITE_SWAPPED_DATA? Did it work before the patch?
FLASH: CFI: Unknown command set 0x0
The command has not been sent but MSB which was 0x00.
## Unknown FLASH on Bank 1 - Size = 0x00000000 = 0 MB
That's the message I got before my patch. There is probably still something wrong.
Please explain what exactly you need to fix, perhaps with an example. The current version breaks other boards.
I attached a file which can be used for testing. On your little endian machine you should have __LITTLE_ENDIAN defined and your result should be 0xf0 in the case i = 0. Right now, I get 0x00 on my BE machine while LE case is working fine.
Sebastian