[PATCH v2 2/2] console: Don't start/stop console if stdio device invalid

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, Feb 03, 2021 at 11:50:53AM +0200, Andy Shevchenko wrote:
> On Mon, Feb 1, 2021 at 9:29 PM Tom Rini <trini@konsulko.com> wrote:
> >
> > On Fri, Jan 29, 2021 at 09:50:50AM +0100, Matthias Brugger wrote:
> > >
> > >
> > > On 28/01/2021 16:52, Andy Shevchenko wrote:
> > > > On Thu, Jan 28, 2021 at 02:12:40PM +0100, Nicolas Saenz Julienne wrote:
> > > >> Don't start/stop an stdio device that might have been already freed.
> > > >>
> > > >> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > > >> Fixes: 70c2525c0d3c ("IOMUX: Stop dropped consoles")
> > > >
> > > > ...
> > > >
> > > >> +  /*
> > > >> +   * TODO: This is a workaround to avoid accessing freed memory:
> > > >> +   * console_stop() might be called on an stdio_dev that has already been
> > > >> +   * de-registered, due to the fact that stdio_deregister_dev()
> > > >> +   * doesn't update the global console_devices array.
> > > >> +   */
> > > >
> > > > I see now. I think I have experienced this issue from time to time. I will look
> > > > at it. Tom, Simon, please hold on applying these for a while.
> > > >
> > >
> > > Just for the notes, the failing tests hold back Nicolas series to support
> > > RPi400/CM4 [1] as it does not run the new tests added successfully. If it takes
> > > a long time to fix the test environment, I'd vote to take this series as a
> > > stop-gap so that we can support that HW in the next release.
> >
> > Andy, since you're working on a better solution, do you want more time
> > for that or should I pick this series up for now and you can revert it
> > as part of your better fix?  Thanks!
> 
> Sorry for the delayed reply. Give me a couple of days, and if I will
> come up without any (good) solution, apply this series.

Okay, as promised, I prepared a branch [1] with new approach, but while I will
be busy with other stuff, I would like you to test on real hardware and tell if
it helps. At least it passes test cases.

If it works, I would like to get a Tested-by tag and will prepare and submit
the formal series.

[1]: https://github.com/andy-shev/u-boot/tree/iomux

-- 
With Best Regards,
Andy Shevchenko