[U-Boot] [PATCH] serial: Make full device search optional

[Alexander Graf]

On 05.02.18 01:39, Derald Woods wrote:
> On Tue, Jan 30, 2018 at 7:34 AM, Alexander Graf <agraf at suse.de
> <mailto:agraf at suse.de>> wrote:
> 
>     On 01/30/2018 02:09 PM, Derald Woods wrote:
> 
>         On Jan 30, 2018 3:17 AM, "Alexander Graf" <agraf at suse.de
>         <mailto:agraf at suse.de> <mailto:agraf at suse.de
>         <mailto:agraf at suse.de>>> wrote:
> 
>             On 01/30/2018 12:41 AM, Derald D. Woods wrote:
> 
>                 On Mon, Jan 29, 2018 at 07:46:09AM -0600, Derald Woods
>         wrote:
> 
>                     On Jan 29, 2018 6:57 AM, "Alexander Graf"
>         <agraf at suse.de <mailto:agraf at suse.de>
>                     <mailto:agraf at suse.de <mailto:agraf at suse.de>>> wrote:
> 
>                     Commit 608b0c4ad4e5ec0c ("serial: Use next serial device
>                     if probing fails")
>                     added code to search for more serial devices if the
>                     default one was not
>                     probed correctly.
> 
>                     Unfortunately, that breaks omap3_evm. So while
>                     investigating why that is
>                     the case, let's disable the full search for everyone but
>                     bcm283x where it
>                     is needed.
> 
>                     Fixes: 608b0c4ad4e5ec0c ("serial: Use next serial device
>                     if probing fails")
>                     Reported-by: Derald D. Woods
>         <woods.technical at gmail.com <mailto:woods.technical at gmail.com>
>                     <mailto:woods.technical at gmail.com
>         <mailto:woods.technical at gmail.com>>>
>                     Signed-off-by: Alexander Graf <agraf at suse.de
>         <mailto:agraf at suse.de>
>                     <mailto:agraf at suse.de <mailto:agraf at suse.de>>>
> 
>                     ---
> 
>                     Derald, could you please test this patch and verify it
>                     does indeed unbreak
>                     omap3_evm?
> 
>                 The omap3_evm boots now with this patch applied on
>         master. If
>                 I enable
>                 SERIAL_SEARCH_ALL, it does not boot. I always build cleanly
>                 using the
>                 default config only. On failure, there is no console
>                 input/output and
>                 the board unresponsive.
> 
> 
>             So SPL is already broken? Can you try a known working SPL with
>             SERIAL_SEARCH_ALL=y U-Boot payload on top? Does that work?
> 
> 
>         I will give that path a try and see what I can discover. Again,
>         it will be later today or tomorrow before I can get to this.
>         This is why I asked what should the board code actually look
>         like. As the omap3_evm is ahead of some other OMAP34XX boards
>         currently, a good working example would be helpful. If omap3_evm
>         becomes the example, let's make it a good one.
> 
> 
>     If you want to make it a good example, don't disable
>     CONFIG_EFI_LOADER :).
> 
>     But really, the only major difference I saw between beagle and evm
>     was the fact that evm used DM in SPL. I patched that up locally (had
>     to remove ext support as the binary became too big otherwise), but
>     that didn't show the issue either. So we'll have to wait on your test
>     ​s.
> 
> 
>  
> ​It looks like some compiler issue is causing the problem. I was using
> GCC 7.2.0. When I go back to GCC 6.4.0 the board boots with
> SERIAL_SEARCH_ALL=y. I also verified this by enabling SPL_DM_SERIAL on
> 'omap3_beagle' and booting with SERIAL_SEARCH_ALL=y. Both GCC versions
> compiled without error. GCC 6.4.0 is the compiler version that is
> working for me now. The actual offending generated code will take more
> time, for me, to sort through.

Can you somehow make it break with omap3_beagle? I have one of those and
could then help debug.


Alex