From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH] i2c: Prevent runtime suspend of adapter when Host Notify is required Date: Thu, 2 May 2019 18:43:46 +0200 Message-ID: <20190502164346.GE11535@kunai> References: <20190430142322.15013-1-jarkko.nikula@linux.intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="lkTb+7nhmha7W+c3" Return-path: Content-Disposition: inline In-Reply-To: <20190430142322.15013-1-jarkko.nikula@linux.intel.com> Sender: stable-owner@vger.kernel.org To: Jarkko Nikula Cc: linux-i2c@vger.kernel.org, Keijo Vaara , linux-input@vger.kernel.org, Bjorn Helgaas , "Rafael J . Wysocki" , stable@vger.kernel.org List-Id: linux-input@vger.kernel.org --lkTb+7nhmha7W+c3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 30, 2019 at 05:23:22PM +0300, Jarkko Nikula wrote: > Multiple users have reported their Synaptics touchpad has stopped > working between v4.20.1 and v4.20.2 when using SMBus interface. >=20 > The culprit for this appeared to be commit c5eb1190074c ("PCI / PM: Allow > runtime PM without callback functions") that fixed the runtime PM for > i2c-i801 SMBus adapter. Those Synaptics touchpad are using i2c-i801 > for SMBus communication and testing showed they are able to get back > working by preventing the runtime suspend of adapter. >=20 > Normally when i2c-i801 SMBus adapter transmits with the client it resumes > before operation and autosuspends after. >=20 > However, if client requires SMBus Host Notify protocol, what those > Synaptics touchpads do, then the host adapter must not go to runtime > suspend since then it cannot process incoming SMBus Host Notify commands > the client may send. >=20 > Fix this by keeping I2C/SMBus adapter active in case client requires > Host Notify. >=20 > Reported-by: Keijo Vaara > Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D203297 > Fixes: c5eb1190074c ("PCI / PM: Allow runtime PM without callback functio= ns") > Cc: stable@vger.kernel.org # v4.20+ > Signed-off-by: Jarkko Nikula Applied to for-current-fixed, thanks! --lkTb+7nhmha7W+c3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlzLHkIACgkQFA3kzBSg KbapUw/9HnAdtGdXtSUvcCCDZyaj63rtRr7jniT8OaAnIjxxSc0xYa8lH5ZnXbSy igBMbL7aluqtHG3T3RkiNdAaT2FIs4le5jWfH7ypxBz2nr8XlUuSayA/ogrSm1XU uhLKNoPamnouY90dpuvu8wUej8WS9sSPHVayu1AYKYTDOnVYwl3cqPnmQw7DzdWg SXJZ7MyfpzTm0S9QBUtzWFkFaty2DtyuWwf7rDo18crnJo+DqslztO1By81Xc41p GFScFOBvHXdyY38eHMrDo851sns2WHPeoTox3x3Un0oXHEYg1m67urD1+xK13oOf AETuz8kwfeXc/z1hrsv4b9jCKFgYUOXStOc4o/Ig6R6R9Y2rEJi141hLoVEBhv0x y2jDsB4RCbsF5pTcJ+L98QCEb1XihELU3VoYvx2HwpgIgbqh/0OgQpqwof2XSMyd 97XrZf9rCAMLeOyElPat5j7EUPPsw1o2ebf2921lJYfTDjIQyp8pRsLcH967zX4d sjtcmRACBgDqdMF/DsShHr25mTJtEg47dvoUWLx98uDj2ryDMdkZmgMhVooAs21t fjE/oJ8jTZURPiMoHhs6rEx0FgoUN0KgpOf5rMMY92SzB5NdnCdHVteZuIklgQZw 52S/MxLZpMPWxPfw7qtWWssSdd1+qIKHn0fCAsMZIoNLgBJGDN4= =m1ON -----END PGP SIGNATURE----- --lkTb+7nhmha7W+c3--