Re: [U-Boot] [PATCHv2 CFI flash]: Workaround for Numonyx Axcell P33/P30 256-Mbit 65nm bug

Hi Stefan,

On Mon, Aug 09, 2010 at 03:52:03PM +0200, Stefan Roese wrote:

Hi Philippe,

first sorry for the late review (thanks Wolfgang for reminding).

On Saturday 07 August 2010 01:11:02 Wolfgang Denk wrote:

...

Dear Stefan,

In message 20100623131040.GA23209@frolo.macqel Philippe De Muyter wrote:

...

Hello Wolfgang & list,

This is a revised patch, with comments and indentation fixed, I hope.

Minor note: Such commentary lines should be moved below the "---" line below. They shouldn't appear in the git history.

<snip>

...

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c index 3267c5d..4bf0807 100644 --- a/drivers/mtd/cfi_flash.c +++ b/drivers/mtd/cfi_flash.c @@ -1347,17 +1347,34 @@ int flash_real_protect (flash_info_t * info, long sector, int prot)

    switch (info->vendor) {

            case CFI_CMDSET_INTEL_PROG_REGIONS:

            case CFI_CMDSET_INTEL_STANDARD:

•           case CFI_CMDSET_INTEL_EXTENDED:
  

•                   flash_write_cmd (info, sector, 0,
  

•                                    FLASH_CMD_CLEAR_STATUS);
  

•                   flash_write_cmd (info, sector, 0, FLASH_CMD_PROTECT);
  

•           case CFI_CMDSET_INTEL_EXTENDED: {
  

•                   unsigned short cmd;
  

•                   if (prot)
  
  

•                           flash_write_cmd (info, sector, 0,
  

•                                   FLASH_CMD_PROTECT_SET);
  

•                           cmd = FLASH_CMD_PROTECT_SET;
  
                    else
  
  

•                           cmd = FLASH_CMD_PROTECT_CLEAR;
  

Please move this variable declaration of "cmd" and assignment further down (see below). You can remove the "{" "}" of this block then.

Here is the excerpt from the errata :

Workaround: If the interval between 60h and its subsequent command can be guaranteed within 20μs, Option I is recommended, otherwise Option II (involves hardware) should be selected. Option I: The table below lists the detail command sequences: Command Data bus Address bus Remarks Sequence 1 90h Block Address Read Lock Status 2 Read Block Address + 02h (2)(3) (1) 3 60h Block Address (2)(3) (1) Lock/Unlock/RCR Configuration 4 D0h/01h/03h Block Address Notes: (1) Block Address refers to RCR configuration data only when the 60h command sequence is used to set RCR register combined with 03h subsequent command. (2) For the third and fourth command sequences, the Block Address must be the same. (3) The interval between 60h command and its subsequent D0h/01h/2Fh/03h commands should be less than 20μs.

Because of requirement (3), I choosed to minimize the number of instructions between the `read lock status' and the `unlock' commands, hence the initialisation of `cmd' moved before the `read lock status' (hidden in `flash_isequal').

...

•                   /*
  

•                    * see errata called
  

•                    * "Numonyx Axcell P33/P30 Specification Update" :)
  

•                    */
  

•                   flash_write_cmd (info, sector, 0, FLASH_CMD_READ_ID);
  

•                   if (!flash_isequal (info, sector, FLASH_OFFSET_PROTECT,
  

•                                       prot)) {
  

•                           int flag = disable_interrupts ();
  

Declare and assign "cmd" here please.

Please change and resubmit. Thanks.

If you still prefer it changed, speak :)

Best regards

Philippe