[PATCH 0/1] fw_setenv always locks flash whenever it tries to write

[Ivan Mikhaylov]

On Fri, 2020-07-10 at 19:54 +0300, Ivan Mikhaylov wrote:
> fw_setenv usage always locks u-boot-env mtd device without questions.
> Locking of flash can be disruptive and may affect not only u-boot-env
> region due to different problems with chips and lock callbacks on
> kernel
> side. I'm not sure if my fix is right, but also I thought about
> possible option
> in fw_env config about locking/unlocking or even option into
> fw_setenv/printenv. Any ideas?
> 
> Ivan Mikhaylov (1):
>   fw_setenv: lock the flash only if it was locked before
> 
>  tools/env/fw_env.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)
> 

A little bit more description:

With current implementation of fw_setenv, it is always locks u-boot-env 
region if lock interface is implemented for such mtd device. You can
not control lock of this region with fw_setenv, there is no option for
it in config or in application itself. Because of this situation may
happen problems like in this thread on xilinx forum:
https://forums.xilinx.com/t5/Embedded-Linux/Flash-be-locked-after-use-fw-setenv-from-user-space/td-p/1027851

Short desc link: some person has issue with some spi chip which has
lock interface but doesn't locks properly which leads to lock of whole
flash memory on lock of u-boot-env region. As resulted solution hack
was added into spi-nor.c driver for this chip with lock disablement.

And for solving such issue usually:
1. do manual unlock after each fw_setenv usage.
2. do hacks inside driver representing your device, as example in spi-
nor.c linux driver.

And, yes, in this case it is problem of two sides:
1. driver lock implementation for some chips.
2. fw_setenv's way of work which is not trying be convenient in this
case and is not providing any option for not doing locks.

I want to implement some mechanism which will help user do not lock
flash when it's not needed. So there is some points how it can be:
1. lock this region if it's already locked.
2. add option into fw_setenv application.
3. add some option about locks into fw_env.config.

Patch what I've, just dirty implementation of first one.
Any ideas or suggestions?