From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH AUTOSEL for 4.14 065/110] led: core: Fix brightness setting when setting delay_off=0 Date: Tue, 13 Mar 2018 14:27:48 +0100 Message-ID: <20180313132748.GA20246@amd> References: <20180204090531.GA29468@amd> <20180204111500.GB14797@kroah.com> <20180204171736.GA1388@amd> <20180206020210.m6gl7vai4p6azb6s@sasha-lappy> <713113d8-7662-d80c-c62f-af020469d0bf@gmail.com> <20180312152811.GB16944@kroah.com> <5747831a-b237-aa2c-cb47-9773cd2b5956@universe-factory.net> <0cd72fe4-2b98-e6f7-6ae7-530524786cec@gmail.com> <20180313093703.GB27669@kroah.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="OgqxwSJOaUobr8KG" Return-path: Content-Disposition: inline In-Reply-To: <20180313093703.GB27669@kroah.com> Sender: linux-kernel-owner@vger.kernel.org To: Greg KH Cc: Jacek Anaszewski , Matthias Schiffer , Sasha Levin , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , Matthieu CASTET , "linux-leds@vger.kernel.org" List-Id: linux-leds@vger.kernel.org --OgqxwSJOaUobr8KG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > > At least 7b6af2c531 ("leds: core: Fix regression caused by commit > > > 2b83ff96f51d") is missing, causing visible regressions (LEDs not work= ing at > > > all) on some OpenWrt devices. This was fixed in 4.4.121 by reverting = the > > > offending commit, but if I followed the discussion correctly, 4.9 sho= uld > > > get the follow-up commit 7b6af2c531 instead (like 4.14 already did). > > >=20 > > > Jacek's mail I replied to mentions that eb1610b4c273 ("led: core: Fix > > > blink_brightness setting race") should be included in 4.9 as well, bu= t I > > > don't know the impact of the issue it fixes. > >=20 > > It doesn't fix any reported issue, but is just an improvement > > aiming at preventing potential races while changing blink brightness. > >=20 > > After taking closer look it turns out that for the patches in question > > to apply cleanly we need in 4.9 also a patch which introduces atomic > > bit fields for blink flags. > >=20 > > Effectively, here is the list of patches required in 4.9 stable: > >=20 > > Revert "led: core: Fix brightness setting when setting delay_off=3D0" > >=20 > > followed by: > >=20 > > a9c6ce57ec ("led: core: Use atomic bit-field for the blink-flags") > > eb1610b4c2 ("led: core: Fix blink_brightness setting race") > > 2b83ff96f5 ("led: core: Fix brightness setting when setting delay_off= =3D0") > > 7b6af2c531 ("leds: core: Fix regression caused by commit 2b83ff96f51d") >=20 > Odd, I just got another report that the 4.9.87 release fixed some > reported LED issues, so why do I need all of these? >=20 > Should I just revert the single 2b83ff96f51d commit here instead? I believe so, yes. I'm not aware of any _really bad_ issues with LED subsystem in 4.9. Take a look at changelog of 2b83ff96f51d0b039c4561b9f95c824d7bddb85c -- it fixes rather theoretical issue; user can reproduce it by hand in shell, but, well... don't do it then. The rest of fixes ... fix some more theoretical races. I don't think it is -stable material, as I pointed out before. Best regards, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --OgqxwSJOaUobr8KG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlqn0dQACgkQMOfwapXb+vKZTwCgpCZaexLrN23mORvHiMe4/dJu 8koAoLdpi2/7/21hWSl3YGY5SS+uShI8 =y1T1 -----END PGP SIGNATURE----- --OgqxwSJOaUobr8KG--