[U-Boot] [PATCH 1/2] serial: add skipping init option

[Lukasz Majewski]

Hi Simon, Jun,

> Hi Jun,
> 
> On Fri, 22 Mar 2019 at 16:02, Jun Nie <jun.nie at linaro.org> wrote:
> >
> > Simon Glass <sjg at chromium.org> 于2019年3月22日周五 下午3:56写道：  
> > >
> > > Hi Jun,
> > >
> > > On Fri, 22 Mar 2019 at 15:20, Jun Nie <jun.nie at linaro.org>
> > > wrote:  
> > > >
> > > > add skipping init option to avoid corrupt data in console
> > > > if serial is already initilized when u-boot start its excution.
> > > >
> > > > Signed-off-by: Jun Nie <jun.nie at linaro.org>
> > > > ---
> > > >  drivers/serial/Kconfig | 6 ++++++
> > > >  1 file changed, 6 insertions(+)  
> > >
> > > Could we use a device-tree property for this? Some UARTs have a
> > > 'skip-init' property.
> > >
> > > Regards,
> > > Simon  
> >
> > Hi Simon,
> >
> > It is a good suggestion. But device tree is board specific, while
> > the config is boot flow specific. For ATF -> OPTEE -> U-BOOT case,
> > initialization should be skipped. Without earlier initialization
> > from firmware, U-boot should do it by itself. So I need find a
> > solution that is defconfig specific, instead of device tree
> > specific.  
> 
> So you want something that is flow-specific, I think. Your thinking is
> that the defconfig specifies this. Is that because certain boards
> require ATF/Optee?
> 
> Should we consider having a way to tell U-Boot that it is running
> from Optee?
> 
> Could the UART driver detect that the UART is already inited?

Isn't this issue similar to:
http://patchwork.ozlabs.org/patch/820824/

and 

http://patchwork.ozlabs.org/patch/865963/

> 
> Regards,
> Simon
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> https://lists.denx.de/listinfo/u-boot




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20190327/a0f278e7/attachment.sig>