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

[Tom Rini <trini@konsulko.com>]

On Thu, Jul 23, 2020 at 10:20:55PM +0000, Ivan Mikhaylov wrote:
> 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?

Thanks.  I've taken the above and updated the commit message more.  I'm
currently reviewing the patch with other env changes now.

-- 
Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 659 bytes
Desc: not available
URL: <https://lists.denx.de/pipermail/u-boot/attachments/20200730/a8d62d61/attachment.sig>