From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?q?Roh=C3=A1r?= Subject: Re: dell-laptop and separate AC timeouts on some Dell systems Date: Fri, 7 Apr 2017 23:55:20 +0200 Message-ID: <201704072355.20831@pali> References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1575376.bSu48zKBhQ"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wm0-f49.google.com ([74.125.82.49]:35588 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756367AbdDGVzZ (ORCPT ); Fri, 7 Apr 2017 17:55:25 -0400 Received: by mail-wm0-f49.google.com with SMTP id w64so1700775wma.0 for ; Fri, 07 Apr 2017 14:55:24 -0700 (PDT) In-Reply-To: Sender: platform-driver-x86-owner@vger.kernel.org List-ID: To: Mario.Limonciello@dell.com Cc: platform-driver-x86@vger.kernel.org --nextPart1575376.bSu48zKBhQ Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Hi! On Friday 07 April 2017 21:33:53 Mario.Limonciello@dell.com wrote: > Pali, >=20 > For some time there have been folks reporting some issues where > keyboard backlight setting is failing on various Dell systems > (https://github.com/dell/libsmbios/issues/3). I've been circling > around internally to find out what's going on. This affects a number > of systems from the last year or so. Great! > What is happening is that some platforms support an alternate > keyboard timeout while on AC. The old "timeout" value is treated as > just a battery timeout and the separate value is the AC timeout. > Unfortunately if the AC timeout is /not/ set in the timeout > setting/update request, this will fail. So in case notebook is running on AC and we want to change timeout for=20 keyboard backlight, we need to tell smbios two timeouts, one for battery=20 and one for AC? > As a result I prototyped a few changes for this at the libsmbios > branch here: > https://github.com/dell/libsmbios/commits/fix-g8-keyboard-backlight Can you update also documentation which is at the end of file? It would=20 help for kernel implementation. > It's not yet requested for merging because I still don't know why > the request to supported features returns "Always On" still (that > shouldn't be supported). It looks like that "Always On" mode is reported by smbios by supported,=20 but setting it will cause failure. Any idea where is a problem? Probably=20 Dell firmware bug? Or needs to be that mode handled specially? > As far as I can tell this doesn't really map well to how the keyboard > backlight driver in the kernel works today, so I wanted to raise > this to you to discuss what the best way to handle it is. One of > these systems can be detected by the presence of the token 0x451.=20 > When that is found, the additional timeout unit and value should be > sent with the requests. >=20 > Can you let me know your thoughts? I think that extending struct kbd_state should work. There are already functions dell_send_intensity() and=20 dell_get_intensity() which handle state based on battery/AC mode. =2D-=20 Pali Roh=C3=A1r pali.rohar@gmail.com --nextPart1575376.bSu48zKBhQ Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEABECAAYFAljoCsgACgkQi/DJPQPkQ1Ks0ACcDWcczCpiwEmngrekk42mRlLa fW8AoKr4xhN+2e2fsF4B8DRQEb790/Py =zAD/ -----END PGP SIGNATURE----- --nextPart1575376.bSu48zKBhQ--