Re: [PATCH] HID: logitech-hidpp: Handle timeout differently from busy

From: Benjamin Tissoires <benjamin.tissoires@redhat.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Linux regressions mailing list" <regressions@lists.linux.dev>,
	"Jiri Kosina" <jikos@kernel.org>,
	"Bastien Nocera" <hadess@hadess.net>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Peter F . Patel-Schneider" <pfpschneider@gmail.com>,
	"Filipe Laíns" <lains@riseup.net>,
	"Nestor Lopez Casado" <nlopezcasad@logitech.com>,
	"Mark Lord" <mlord@pobox.com>
Subject: Re: [PATCH] HID: logitech-hidpp: Handle timeout differently from busy
Date: Wed, 7 Jun 2023 12:07:21 +0200	[thread overview]
Message-ID: <CAO-hwJJxZuXP=kgTxEc-F+OtcFsR59iGE3Vw3ptZs48+MotNtA@mail.gmail.com> (raw)
In-Reply-To: <2023060703-colony-shakily-3514@gregkh>

On Wed, Jun 7, 2023 at 11:46 AM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Tue, Jun 06, 2023 at 08:37:26PM +0200, Benjamin Tissoires wrote:
> > On Tue, Jun 6, 2023 at 8:18 PM Linux regression tracking (Thorsten
> > Leemhuis) <regressions@leemhuis.info> wrote:
> > >
> > >
> > >
> > > On 06.06.23 15:27, Jiri Kosina wrote:
> > > > On Mon, 5 Jun 2023, Linux regression tracking (Thorsten Leemhuis) wrote:
> > > >
> > > >>>>> If an attempt at contacting a receiver or a device fails because the
> > > >>>>> receiver or device never responds, don't restart the communication, only
> > > >>>>> restart it if the receiver or device answers that it's busy, as originally
> > > >>>>> intended.
> > > >>>>>
> > > >>>>> This was the behaviour on communication timeout before commit 586e8fede795
> > > >>>>> ("HID: logitech-hidpp: Retry commands when device is busy").
> > > >>>>>
> > > >>>>> This fixes some overly long waits in a critical path on boot, when
> > > >>>>> checking whether the device is connected by getting its HID++ version.
> > > >>>>>
> > > >>>>> Signed-off-by: Bastien Nocera <hadess@hadess.net>
> > > >>>>> Suggested-by: Mark Lord <mlord@pobox.com>
> > > >>>>> Fixes: 586e8fede795 ("HID: logitech-hidpp: Retry commands when device is busy")
> > > >>>>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217412
> > > >>> [...]
> > > >>>>
> > > >>>> I have applied this even before getting confirmation from the reporters in
> > > >>>> bugzilla, as it's the right thing to do anyway.
> > > >>>
> > > >>> Unfortunately it doesn't seem to cure the reported issue (while reverting
> > > >>> 586e8fede79 does):
> > > >>
> > > >> BTW, remind me again: was fixing this by reverting 586e8fede79 for now a
> > > >> option? I guess it's not, but if I'm wrong I wonder if that might at
> > > >> this point be the best way forward.
> > > >
> > > > This should now all be fixed by
> > > >
> > > >     https://git.kernel.org/linus/7c28afd5512e371773dbb2bf95a31ed5625651d9
> > >
> > > Jiri, Benjamin, many many thx for working on this.
> > >
> > > Hmmm. No CC: <stable... tag.
> > >
> > > Should we ask Greg to pick this up for 6.3 now, or better wait a few
> > > days? He currently already has 6199d23c91ce ("HID: logitech-hidpp:
> > > Handle timeout differently from busy") in his queue for the next 6.3.y
> > > release.
> >
> > Well, the Fixes: tag supposedly is enough to let the stable folks to
> > pick it up.
>
> No, not at all, please see:
>     https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> for how to do this properly.
>
> (hint, we need a cc: stable@ in the signed-off-by area.)
>
> We only pick up stuff with "Fixes:" semi-often, sometimes never,
> depending on our workload.  Never rely on that.

Oh right. Given that those patches eventually end up in stable sooner
or later I made the shortcut in my head. Thanks for correcting that :)

>
> It's been this way for 18+ years now, nothing new :)
>
> > But you are right, let's Cc Greg for a quicker inclusion
> > in the 6.3 tree.
> >
> > Greg, would you mind adding the commit above (7c28afd5512e37) onto the
> > 6.3 stable queue? Thanks!
>
> Now queued up, thanks.

Great thanks!

Cheers,
Benjamin