Re: kernel hang during reboot when cmdline include a non-exist console device

[James Wang]

在 2021/8/31 PM10:52, Petr Mladek 写道:
> On Tue 2021-08-31 22:38:42, James Wang wrote:
> > 在 2021/8/31 PM10:33, Petr Mladek 写道:
> > > On Tue 2021-08-31 21:45:05, James Wang wrote:
> > > > 在 2021/8/31 PM4:47, Sergey Senozhatsky 写道:
> > > > > And may I ask, just in case, if James can revert a revert of Petr's commit:
> > > > >
> > > > >           revert a91bd6223ecd46addc71ee6fcd432206d39365d2
> > > > >
> > > > > boot with wrong console argument and see if the kernel reboots without
> > > > > any problems.
> > > > After test, revert Petr's commit can work; reboot without any problem;
> > > Interesting, it looks like the panic() is really caused by missing
> > > stdout, stdin, and stderr, for the init process.
> > >
> > > Unfortunately, the fix is not easy, as described in the commit
> > > a91bd6223ecd46addc71e ("Revert "init/console: Use ttynull as
> > > a fallback when there is no console").
> > OK. But I suppose you could find a quick workaround to mitigate this issue.
> You could either remove the invalid console=ttyUSB0,115200
> parameter. As a result, tty0 will become the default console and
> it will be used by the init process.

No，I just want to use a "invalid" console parameter for "boot up", 
because It could help me "drop" kernel/systemd log, keep the kernel logo 
on the screen;


James