From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 822FBC4332F for ; Wed, 27 Apr 2022 09:09:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232596AbiD0JNA (ORCPT ); Wed, 27 Apr 2022 05:13:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231888AbiD0JM5 (ORCPT ); Wed, 27 Apr 2022 05:12:57 -0400 Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2803246D83; Wed, 27 Apr 2022 02:09:39 -0700 (PDT) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 23R98wKe096536; Wed, 27 Apr 2022 04:08:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1651050538; bh=tZmsedJBK+wypmz7ZMqScfecunctYA+e1BUCoMpA3L4=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=aNfVUh7g1x6SSD48M99Ff/4BfgX2xIgk20xloWFGn2DZOwb6C4UQNueXNmoc5rX8q Fix8K9rBfJy52f4c/WYJiClyQOV5OV7uY4urfp6JZexhEiRJVDSDX7Qcvco0O4dmDA KgmXQWf/280bXfNImmOOtpSONwFW9EfJHoOe2GcQ= Received: from DLEE112.ent.ti.com (dlee112.ent.ti.com [157.170.170.23]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 23R98waq011856 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 27 Apr 2022 04:08:58 -0500 Received: from DLEE100.ent.ti.com (157.170.170.30) by DLEE112.ent.ti.com (157.170.170.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Wed, 27 Apr 2022 04:08:57 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE100.ent.ti.com (157.170.170.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14 via Frontend Transport; Wed, 27 Apr 2022 04:08:57 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 23R98utF008682; Wed, 27 Apr 2022 04:08:57 -0500 From: Aradhya Bhatia To: Vignesh Raghavendra CC: Nishanth Menon , Rob Herring , Linux ARM Kernel List , Devicetree List , Linux Kernel List , Aradhya Bhatia Subject: [PATCH 3/4] arm64: dts: ti: k3-am625-sk: Update main-i2c1 frequency Date: Wed, 27 Apr 2022 14:38:49 +0530 Message-ID: <20220427090850.32280-4-a-bhatia1@ti.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220427090850.32280-1-a-bhatia1@ti.com> References: <20220427090850.32280-1-a-bhatia1@ti.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Update the main-i2c1 frequency from 400KHz to 100KHz. There are 2 devices on the i2c-1 bus. An IO-Expander and an HDMI TX. Both of these are capable of servicing i2c upto a max frequency of 400KHz. However, below warning log shows up while running any userspace application that uses the HDMI display when the main-i2c1 frequency is set at 400KHz. [ 985.773431] omap_i2c 20010000.i2c: controller timed out With some further tests using 2 frequencies, 100 KHz and 400KHz across different HDMI cable & monitor setups, it was observed that, - i2c frequency of 400KHz works fine with standard good quality HDMI cables with branded displays. It will show the controller timeout warnings only when a sub-standard / generic HDMI cable is being used. - Using 100KHz for i2c frequency, stops the warning from showing up for the generic HDMI cables as well. Since, the IO-Expander is the only other component on that i2c bus and we are not performing any intensive operations on it, it would be safe to set the i2c frequency at 100KHz in order to support a broader variety of HDMI cables. Signed-off-by: Aradhya Bhatia --- arch/arm64/boot/dts/ti/k3-am625-sk.dts | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/ti/k3-am625-sk.dts b/arch/arm64/boot/dts/ti/k3-am625-sk.dts index ab3d90d358ee..96414c5dacf7 100644 --- a/arch/arm64/boot/dts/ti/k3-am625-sk.dts +++ b/arch/arm64/boot/dts/ti/k3-am625-sk.dts @@ -357,7 +357,7 @@ &main_i2c0 { &main_i2c1 { pinctrl-names = "default"; pinctrl-0 = <&main_i2c1_pins_default>; - clock-frequency = <400000>; + clock-frequency = <100000>; exp1: gpio@22 { compatible = "ti,tca6424"; -- 2.36.0