[U-Boot] [PATCH] Revert "env: add spi_flash_read_env function"

[Horatiu Vultur]

Hi Heiko,

Sorry, for late reply. I have seen that this patch was accepted, so
I have only few things bellow.

The 03/15/2019 05:34, Heiko Schocher wrote:
> External E-Mail
> 
> 
> Hello Horatiu,
> 
> Am 14.03.2019 um 13:53 schrieb Horatiu Vultur:
> > Hi Heiko,
> > 
> > I managed to reproduce the issue that you described.
> 
> Fine, thanks for testing!
> 
> > Don't you think it is a little bit too harsh to remove the commit
> > completely?
> 
> I am unsure here ...
> 
> > I am not sure but how many cases are where UBoot doesn't store anything
> > in flash? And then lets the linux to update the flash.
> 
> I think that can happen very often. In my case for example we boot
> SPL/U-Boot with usb loader, than an initsystem with kernel/dtb/ramdisk
> and start swupdate for installing all sources (including setup
> the Environment with fw_setenv)...
> 
> > Or is wouldn't better to update fw_setenv to set the entire flash to
> > 0x0 when it detects that the CRC error? The same way how the saveenv it
> > is doing in UBoot?
> 
> Indeed, just reproduced this on my board. Saving the Environment
> with saveenv fills with 0x0 and saving with fw_setenv fills with
> 0xff.
> 
> This is no problem, until your optimization, and I think, we cannot
> change this here without breaking a lot of boards, running fine.
> 
> I am here also on Stefanos side always to read the hole Environment
> space, because we cannot be sure, with what the empty space is filled
> up.
> 
> Back to your intention for this patch, stated in the commit message:
> """
>     This is an optimization for large environments that contain few bytes
>     environment variables. In this case it doesn't need to read the entire
>     environment and only few pages.
> """
> 
> Hmm... why you use a big Environment, if you only have "few bytes" of
> variables ?

We choose a big Environment because different boards can have different
flashes which can have different page size. Therefore we chose for the
environmnet size to be the least common multiple.

> 
> Simply set CONFIG_ENV_SIZE to a smaller value than your CONFIG_ENV_SECT_SIZE
> 
> Is this not possible for you ?

Thanks for the suggestion. I have done few tests with this option and
improves the speed setting the CONFIG_ENV_SIZE to something smaller than
CONFIG_ENV_SECT_SIZE.

> 
> bye,
> Heiko
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-- 
/Horatiu