Flash erase wait time

Flash erase wait time

[Adil Hafeez]

[-- Attachment #1: Type: text/plain, Size: 931 bytes --]

Hi,

I am using a custom mips board that includes 8 MB Am29LV641D flash
chip. This chip is 16-bit, has 128 sectors of 64k each.

This flash is memory mapped and starts at address 1c40:0000. I can
read the flash using dd utility. But I cannot erase flash. Erase
operation using 'eraseall' utility doesnt take more than 6 seconds to
finish and erases only first two blocks i.e. 128k. Whereas, full flash
erase from our custom developed flash utlity takes 60 seconds to erase
flash.

Then after hacking into cmd cfi commad set. The erase issue was fixed by 
adding a while loop for checking polarity bit in do_erase_oneblock function.

while (!sectorDone) {
    unsigned volatile short *flash_addr = adr + map->map_priv_1;
    if( (*flash_addr) & 0x0080 )
        sectorDone = 1;
}

Was it really required to double check the polarity bit, or there are
some timeout timer issues with my mips port ?


- Adil

[-- Attachment #2: erase_all_fix.patch --]
[-- Type: application/octet-stream, Size: 664 bytes --]

Index: drivers/mtd/chips/cfi_cmdset_0002.c
===================================================================
RCS file: /home/embedded/linux-2.4.20_palmchip/drivers/mtd/chips/cfi_cmdset_0002.c,v
retrieving revision 1.1
diff -r1.1 cfi_cmdset_0002.c
240c240
<               cfi->fast_prog = 0;
---
>               cfi->fast_prog = 1;
897a898
>
975a977,989
>     {
>     int sectorDone = 0;
>     while (!sectorDone) {
>         unsigned volatile short *flash_addr = adr + map->map_priv_1;
>         if( (*flash_addr) & 0x0080 )  {
>                 sectorDone = 1;
>         }
>         else {
>         }
>
>     }
>     }
>
1125a1140
>

Re: Flash erase wait time

[Thomas Gleixner]

On Fri, 2005-08-26 at 15:54 +0500, Adil Hafeez wrote:
> Was it really required to double check the polarity bit, or there are
> some timeout timer issues with my mips port ?

1. We have no idea, which version of cfi_cmset_0002.c you are using.
Please provide the $Id string on top of the file. The kernel version and
the applied patches on top of this kernel.

2. If you send patches, read linux/Documentation/SubmittingPatches first

3 . From your patch:

file: /home/embedded/linux-2.4.20_palmchip/drivers/mtd/chips/cfi_cmdset_0002.c,v

Please read
http://www.linux-mtd.infradead.org/source.html#kernelversions

tglx

Re: Flash erase wait time

[Adil Hafeez]

Thanks, Thomas.

I am using 2.4.20 kernel, with Linux MTD framework backported from 2.4.31.

The $id flash in cfi_cmdset_0002.c file is:

$Id: cfi_cmdset_0002.c,v 1.62 2003/01/24 23:30:13 dwmw2 Exp $

Adil

On 8/26/05, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Fri, 2005-08-26 at 15:54 +0500, Adil Hafeez wrote:
> > Was it really required to double check the polarity bit, or there are
> > some timeout timer issues with my mips port ?
> 
> 1. We have no idea, which version of cfi_cmset_0002.c you are using.
> Please provide the $Id string on top of the file. The kernel version and
> the applied patches on top of this kernel.
> 
> 2. If you send patches, read linux/Documentation/SubmittingPatches first
> 
> 3 . From your patch:
> 
> file: /home/embedded/linux-2.4.20_palmchip/drivers/mtd/chips/cfi_cmdset_0002.c,v
> 
> Please read
> http://www.linux-mtd.infradead.org/source.html#kernelversions
> 
> tglx
> 
> 
>