[U-Boot-Users] U-boot ColdFire development

[Liew Tsi Chung-r5aahp]

Wolfgang, Stefan and Detlev,

The CFG_FLASH_USE_BUFFER_WRITE does not help in this case because the intel flash chip on M5329EVB does not support Buffer Write. (It could be verified by reading the CFI at offset 0x2a)

I were doing an experiment days ago by redirected some of the CFI driver functions to board specific flash driver functions. I replaced flash_write_cfiword() in write_buff() to write_data(). Program the flash for 1MB. flash_add_byte() is ~5s more than total time in board specific flash driver. Replaced the write_data() flash status check in while loop - while ((*addr & (u16) FLASH_STATUS_DONE) != (u16) FLASH_STATUS_DONE) to while(!flash_isset (info, sec, 0, FLASH_STATUS_DONE)), this will add another ~11s.

There are some overhead in the CFI flash driver for non Buffer Write. Anyway, I am going to use the CFI flash driver from now on.

Again. Thanks for yours help and comments.

Regards,
TsiChung

-----Original Message-----
From: Stefan Roese [mailto:sr at denx.de] 
Sent: Tuesday, July 03, 2007 3:54 AM
To: Liew Tsi Chung-r5aahp
Cc: Wolfgang Denk; u-boot-users at lists.sourceforge.net
Subject: Re: [U-Boot-Users] U-boot ColdFire development

Hi TsiChung,

On Saturday 30 June 2007, Wolfgang Denk wrote:
> > There is no speed performance in erasing and reading between common 
> > CFI flash driver and board specific flash driver, except 
> > programming. CFI flash driver needs ~80s to program 1MB data compare 
> > to board specific flash driver needs only ~14s. User has a choice to 
> > select them either by
>
> Are you absolutely sure about this? Did you enable 
> CFG_FLASH_USE_BUFFER_WRITE in your board config file?
>
> If yes, then can you please try to explain  *why*  there  is  such  a 
> speed  difference?  In  general,  the CFI driver should be able to do 
> exactly the same what a custom flash driver can  do  -  if  there  is 
> anything missing, it should be added. Patches welcome.

Yes, I would expect when the write buffering is enabled (Wolfgang mentioned the config option above) the programming speed should be the same to your board specific driver.

Best regards,
Stefan

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