From patchwork Thu May 5 13:43:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aradhya Bhatia X-Patchwork-Id: 12839575 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AC416C433EF for ; Thu, 5 May 2022 13:45:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CmEgiAHrQCPecZ72/dOyIP4u4C5BotRoFpIHtlOZc0U=; b=4bFsWyKgGJc4mD S0VdQ8U527+D3t4BqUjUDjXwbYfCrfDGAtMUSuWA4u+/E2ja3jcNE/c4H1GWjPqnqa9VTqDtNuZ1X F9dp2xHwtgCneFOw9zO3+aX1DhMfGDcbzBNXOD2mtcbBW8oUiwL+FxL1A0jjervoTNFpTmXhrl4pV byd54R/NALS3PfP04HOUoF8MEIRfGXc5iyVw9oVgH/6pQ4PM0I72DPlxy5KMsPcTAy3Ttpnrm2bWZ Dg6SM1T55b76TF7qJGFdvuSmmnVtP0dUnu4lPOQpB55BqvTznpN3No4b9a3JISrjMZDevLsq3WOHF DqmtK3HlMd6YXDx1hmxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmbm0-00G77x-Bl; Thu, 05 May 2022 13:44:04 +0000 Received: from fllv0015.ext.ti.com ([198.47.19.141]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nmblJ-00G6kP-RD for linux-arm-kernel@lists.infradead.org; Thu, 05 May 2022 13:43:24 +0000 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 245DhA3u030876; Thu, 5 May 2022 08:43:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1651758190; bh=7PpGp+IxjY/mFC2wCH1dJ/EU5sBQTGAt350jNpBo3oU=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=h2aKHfebjZGw0M5mTyx/EmM6CIDH2KRf6D6PMo2jfhRwr7+GFLgmlQLJ+Ql2vOuUn mCIg/J0s3GM/9h31tAb4eqOENIxWoUkV+9j+APvQN8qPl0cV5eKhJhn7x/BNoxyJUq 0l6ewkMnQF4+Kbpq0brtGnlQK8mzkRA2VfIknR+4= Received: from DFLE114.ent.ti.com (dfle114.ent.ti.com [10.64.6.35]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 245DhA6J053453 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 5 May 2022 08:43:10 -0500 Received: from DFLE101.ent.ti.com (10.64.6.22) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.14; Thu, 5 May 2022 08:43:10 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE101.ent.ti.com (10.64.6.22) 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; Thu, 5 May 2022 08:43:09 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id 245Dh939104707; Thu, 5 May 2022 08:43:09 -0500 From: Aradhya Bhatia To: Vignesh Raghavendra CC: Nishanth Menon , Rob Herring , Linux ARM Kernel List , Devicetree List , Linux Kernel List , Aradhya Bhatia , Rahul T R Subject: [PATCH v2 3/4] arm64: dts: ti: k3-am625-sk: Update main-i2c1 frequency Date: Thu, 5 May 2022 19:13:02 +0530 Message-ID: <20220505134303.23208-4-a-bhatia1@ti.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220505134303.23208-1-a-bhatia1@ti.com> References: <20220505134303.23208-1-a-bhatia1@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220505_064322_139926_F735CFEA X-CRM114-Status: GOOD ( 15.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 Reviewed-by: Rahul T R --- 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";