From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755702AbcI0R0e convert rfc822-to-8bit (ORCPT ); Tue, 27 Sep 2016 13:26:34 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:54550 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753040AbcI0R0Y (ORCPT ); Tue, 27 Sep 2016 13:26:24 -0400 Date: Tue, 27 Sep 2016 19:25:48 +0200 (CEST) From: Stefan Wahren To: eric@anholt.net, wsa@the-dreams.de, swarren@wwwdotorg.org, =?UTF-8?Q?Noralf_Tr=C3=B8nnes?= Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org Message-ID: <256118042.194076.147d5d83-f402-4ba4-b7de-4ab57a0e29ad.open-xchange@email.1und1.de> In-Reply-To: <1474977426-3272-9-git-send-email-noralf@tronnes.org> References: <1474977426-3272-1-git-send-email-noralf@tronnes.org> <1474977426-3272-9-git-send-email-noralf@tronnes.org> Subject: Re: [PATCH v2 8/8] ARM: bcm2835: Disable i2c2 in the Device Tree MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-Priority: 3 Importance: Medium X-Mailer: Open-Xchange Mailer v7.8.0-Rev38 X-Originating-Client: open-xchange-appsuite X-Provags-ID: V03:K0:zoo1BnDzvPvAfqUY+OBXexKWvCtWrgTOzFat02Dr6p5gMohj0Ix shovsLMZMYWw3zT0pTXkPSsSeuSCyMUcPgpPqAFjIdkA3bwqnkwEQ1GUajLQjUrqCGmFS5+ E0hIWnXurGl0Kr8cseGsTz62sxjl+M1twEOiiDYRye/3HbmNEECqqNrHRTw2NEldijcnG5T hevqoDypznZCQSUz+rslw== X-UI-Out-Filterresults: notjunk:1;V01:K0:en5ELQEowkw=:VB0lO/DhC1LqRf2MBnBGPZ fizYE1nolTJdIkuUL528nvcRZvpmF6XpHtfU9tG0D68/th4G5KimxfeFMxrWHEeAnz5a4a1dI SFo5rH0d35JDpVg0WazOT/89ry614vpsGI1zQcXM6wrHUlAO+kMdb/q5ZEFlXe9Alh9Zm8qnq jjRK8Us/wfgcoy+MfTbEAxXfyUti14IgO2yZSkGfhGYqcnIBL7l3W9GOrOC8Y08oNmevue7xo nG4i5W0dQOmCdWM6qYRvk3CLgj4SSN/R7hwFgGXWd2vwaAQL+43VBt3rSor9LHYFVqEKOq6oI 62Ihh6nsO+78viN4mrmaVuMFFep5sqwRY6mpWILoomJ2Shh+YL9+PuVmJ3X1z3KsH2Tfq9EHP 1yiKo7DRLUKosl8XIrHsTiLV+aZRTB9wzETUjV0pKMJfZnd8wHyakULfbXvp9rSKxFfYwpxjz mQXKNp62IgIw/setuiDb7gRYa9LzcbMJ1JZJFjLzUiey+5SfPX0H1HWIafyHXgg0LWHk6Pfl0 Yy1Q3dTW3zLFNszglpemg3BgYSrFu9VolFDl3Huae3b5SbHtgAvXR37eMJmGwD+ZH3L7ltQ2T jMgeoXBeb/TKe1dIf2TYyM0aOuAXPMjqeYyFglnACWw9HvG73HJ5ru76Y5LWyj1fol5xM+MxG wqmM3pWJLSTaRLmyGydx+HCModdLH1MlIVgT0LPpZp7R0veB9nnc7DKsQ28lJibA+BcnE9V8L imVeCZ+rIPblYw2I Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Noralf Trønnes hat am 27. September 2016 um 13:57 > geschrieben: > > > i2c2 is connected to the HDMI connector and is controlled by the > firmware. Disable it to stay out of harms way. Until this point the commit message is okay, the rest is more confusing. Btw this should avoid a warning about missing clock frequency. > > From the downstream commit: > i2c-bcm2708/BCM270X_DT: Add support for I2C2 > > The third I2C bus (I2C2) is normally reserved for HDMI use. Careless > use of this bus can break an attached display - use with caution. > > It is recommended to disable accesses by VideoCore by setting > hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt. > > Signed-off-by: Noralf Trønnes > --- > arch/arm/boot/dts/bcm2835-rpi.dtsi | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi > b/arch/arm/boot/dts/bcm2835-rpi.dtsi > index e9b47b2..8bffbee 100644 > --- a/arch/arm/boot/dts/bcm2835-rpi.dtsi > +++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi > @@ -59,10 +59,6 @@ > clock-frequency = <100000>; > }; > > -&i2c2 { > - status = "okay"; > -}; > - I'm not sure if this the right fix. According to bcm283x.dtsi the 3 i2c busses have the same compatible string "brcm,bcm2835-i2c", but the changelog suggests that this bus is "special". Shouldn't we use a different compatible string? Our intention isn't to disable i2c2 but avoid any claims of the usual i2c driver. > &sdhci { > status = "okay"; > bus-width = <4>; > -- > 2.8.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan.wahren@i2se.com (Stefan Wahren) Date: Tue, 27 Sep 2016 19:25:48 +0200 (CEST) Subject: [PATCH v2 8/8] ARM: bcm2835: Disable i2c2 in the Device Tree In-Reply-To: <1474977426-3272-9-git-send-email-noralf@tronnes.org> References: <1474977426-3272-1-git-send-email-noralf@tronnes.org> <1474977426-3272-9-git-send-email-noralf@tronnes.org> Message-ID: <256118042.194076.147d5d83-f402-4ba4-b7de-4ab57a0e29ad.open-xchange@email.1und1.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > Noralf Tr?nnes hat am 27. September 2016 um 13:57 > geschrieben: > > > i2c2 is connected to the HDMI connector and is controlled by the > firmware. Disable it to stay out of harms way. Until this point the commit message is okay, the rest is more confusing. Btw this should avoid a warning about missing clock frequency. > > From the downstream commit: > i2c-bcm2708/BCM270X_DT: Add support for I2C2 > > The third I2C bus (I2C2) is normally reserved for HDMI use. Careless > use of this bus can break an attached display - use with caution. > > It is recommended to disable accesses by VideoCore by setting > hdmi_ignore_edid=1 or hdmi_edid_file=1 in config.txt. > > Signed-off-by: Noralf Tr?nnes > --- > arch/arm/boot/dts/bcm2835-rpi.dtsi | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi > b/arch/arm/boot/dts/bcm2835-rpi.dtsi > index e9b47b2..8bffbee 100644 > --- a/arch/arm/boot/dts/bcm2835-rpi.dtsi > +++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi > @@ -59,10 +59,6 @@ > clock-frequency = <100000>; > }; > > -&i2c2 { > - status = "okay"; > -}; > - I'm not sure if this the right fix. According to bcm283x.dtsi the 3 i2c busses have the same compatible string "brcm,bcm2835-i2c", but the changelog suggests that this bus is "special". Shouldn't we use a different compatible string? Our intention isn't to disable i2c2 but avoid any claims of the usual i2c driver. > &sdhci { > status = "okay"; > bus-width = <4>; > -- > 2.8.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel