[U-Boot] [PATCH 2/2 V2] IOMUX: Add console multiplexing support.

[Ben Warren <biggerbadderben@gmail.com>]

Wolfgang Denk wrote:
> Dear Gary Jennejohn,
>
> In message <20081020182635.4ed9ca48@ernst.jennejohn.org> you wrote:
>   
>> I looked at this some more.  eth_initialize() is called in every
>> architecture-specific library which means changing 8 files to move
>> it up to before the initialization of netconsole.
>>
>> netconsole is intialized in devices_init() which is called even before
>> console_init_r() and long before eth_initialize().
>>     
>
> Well, maybe there is a less intrusive approach to solve the problem.
>
>   
>> One alrernative which occurs to me would be to introduce a new flag
>> GD_FLG_ETHINIT, but this is even worse because it requires modifying
>> 12 header files and 3 or more C files.
>>     
>
> Hm... let's sum up what exactly the problem is; you wrote:
>
> | This causes problems because u-boot will try to write to nc as soon
> | as GD_FLG_DEVINIT is set in gd->flags, which happens before the
> | network devices are initialized in net/eth.c. This results in error
> | messages being spewed out.
>
> I read this that what we actually want to do is stopping NC to
> transmit too early. Correct?
>
> Well, nc_send_packet() (see "drivers/net/netconsole.c") can be easily
> shortcut if we find a way to make eth_get_dev() return NULL.
>
> And eth_get_dev() (see "net/eth.c") just returns "eth_current".
>
> So maybe there is a way to make sure "eth_current" is set to NULL
> until it's OK for netconsole to transmit?
>
> Maybe, maybe eventually the real  cause  of  your  problems  is  that
> "eth_current"  is  not  read  as NULL while running from flash? Maybe
> changing the declaration in "net/eth.c" into something like this would
> help?
>
> static struct eth_device *eth_current  __attribute__ ((section(".data"))) = NULL;
>
> What do you think?
>
>   
This looks like a good idea.  eth_current is a variable that should 
definitely be in a known state.
> Best regards,
>
> Wolfgang Denk
>
>   
regards,
Ben