Re: [PATCH 1/4] serial: 8250: Avoid error message on reprobe

[Lukas Wunner <lukas@wunner.de>]

On Wed, May 06, 2020 at 01:01:57PM +0300, Andy Shevchenko wrote:
> On Wed, May 06, 2020 at 08:06:23AM +0200, Lukas Wunner wrote:
> > On Tue, May 05, 2020 at 07:01:01PM +0300, Andy Shevchenko wrote:
> > > On Tue, May 05, 2020 at 04:42:01PM +0200, Lukas Wunner wrote:
> > > > Cc: stable@vger.kernel.org # v2.6.10+
> > > 
> > > Fixes tag?
> > 
> > The bug was introduced in the pre-git era, so I can't provide a Fixes tag:
> > 
> > https://git.kernel.org/tglx/history/c/befff6f5bf5f
> > 
> > This commit, which went into v2.6.10, added an unconditional
> > uart_remove_one_port() in serial8250_register_port().
> 
> We have history tree, but I heard you.
> 
> > In 2012, commit 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe")
> > made the call to uart_remove_one_port() conditional on uart->port.dev
> > being non-NULL and that allows me to fix the issue by setting that
> > pointer to NULL in the error path.  The commit went into v3.7, so it
> > should be possible to fix the problem going back to v3.7 with my patch.
> > And before that one needs to additionally make the call to
> > uart_remove_one_port() conditional.
> 
> Perhaps it will be the best candidate.

There's a syntax to specify prerequisites which is documented in:
Documentation/process/stable-kernel-rules.rst

So I intend to do the following:

Cc: stable@vger.kernel.org # v2.6.10
Cc: stable@vger.kernel.org # v2.6.10: 835d844d1a28: 8250_pnp: do pnp probe before legacy

And it probably doesn't hurt to include the explanation above
(which historic commit I'm fixing and so on) in the commit message.

Thanks,

Lukas