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 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 6794910A88E1 for ; Thu, 26 Mar 2026 15:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8hjbkzpYN6SEyYHTqhvZQT64dEOhLI3aoAivH4zr/qc=; b=soJ6Z1+LxASbhm22lMtvUqMFAk kLngdJIUDgpWoOdSEUPcgXBClFfgpJMnf4Fu+kbcBrKUSltdwHaWd2EBTHTn9bsDp+WyH8xBqASOO C34tCtgmBNF8Igh5ksqiw/45A3w5aTub+uemDS+ExVvFy+4Yn6bWcAzm3JTv3XQu9MFVpbsDSmIc+ gsy3Xi3Mn7XVCrTGk8e9TAHsh8ffZCTQPhMb5N1Bro7XwVSywKw6UdZOclgX2IBut5kQCfhG/b5a3 pAojGrkGQXGXAUOtdK98UzFtVUeG4LFshD2rP6tfmq/m/EGUf4mO6FiBHqj5KTdDOiYdzNljGVPAw 1Prb53wg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w5n6i-00000005oMs-1IMz; Thu, 26 Mar 2026 15:58:52 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w5n6f-00000005oM8-2XjG for linux-arm-kernel@lists.infradead.org; Thu, 26 Mar 2026 15:58:50 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id F2CF843C57; Thu, 26 Mar 2026 15:58:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01FFDC116C6; Thu, 26 Mar 2026 15:58:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774540728; bh=tTQxD9EHRYahV5vajLwoH5cOmwDwYqTZzE3aTrnmmRA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BAcWM7ct+tSe96JXMXQjjuR+xRmsdakYqdUam7sAe1arIjeds+uoCtqwyQEcnIwRm oddaBY8DCQZMFEmELY6vZXE18Hh4Hp/gHAEjydww9YpcK3OfHb7OQot5VlMtVUEQlj yS5mxCVqf6t6luH62UWpXv2e3AP9Ro6DkJ7Fa+rw5/rDi0deE/gIE25empz+u2mTZT 77IMGTOkIvrEsbnJs7pQImnJiaEZAjkISToUzlxFFR1t3+2EqIprUULe3I39IQlDNL KposIUGT64pgRYNa9w0hhwRwBl8ZnKwDoBdM51MZzhorgldWQWp+QuD+4ur1MOXKJ/ gLEJIvjbsTQQQ== Date: Thu, 26 Mar 2026 10:58:45 -0500 From: Bjorn Andersson To: Ayushi Makhija Cc: konrad.dybcio@linaro.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, dmitry.baryshkov@linaro.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, quic_rajeevny@quicinc.com, quic_vproddut@quicinc.com Subject: Re: [PATCH] arm64: dts: qcom: sm8750-mtp: Set sufficient voltage for panel nt37801 Message-ID: References: <20260323102229.1546504-1-quic_amakhija@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260326_085849_684327_54F53A06 X-CRM114-Status: GOOD ( 23.58 ) 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 On Thu, Mar 26, 2026 at 03:06:52PM +0530, Ayushi Makhija wrote: > On 3/24/2026 7:34 AM, Bjorn Andersson wrote: > > On Mon, Mar 23, 2026 at 03:52:29PM +0530, Ayushi Makhija wrote: > >> The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states > >> VDDI=1.65V~1.95V, so set sufficient voltage for panel nt37801. > >> > > > > Please add Fixes: tag. > > > > Hi Bjorn, > > Sure, will add in new patchset. > > >> Signed-off-by: Ayushi Makhija > > > > Please start using your oss.qualcomm.com address. > > > >> --- > >> arch/arm64/boot/dts/qcom/sm8750-mtp.dts | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts > >> index 3837f6785320..6ba4e69bf377 100644 > >> --- a/arch/arm64/boot/dts/qcom/sm8750-mtp.dts > >> +++ b/arch/arm64/boot/dts/qcom/sm8750-mtp.dts > >> @@ -462,7 +462,7 @@ vreg_l11b_1p0: ldo11 { > >> > >> vreg_l12b_1p8: ldo12 { > >> regulator-name = "vreg_l12b_1p8"; > >> - regulator-min-microvolt = <1200000>; > >> + regulator-min-microvolt = <1650000>; > > > > Are you sure it's not supposed to be 1.8V, given the name of the rail? > > > > Regards, > > Bjorn > > There was already discussion regarding the minimum voltage for this regulator on sm8550 target > on other upstream patch. > > Link: https://lore.kernel.org/all/aQQdQoCLeKhYtY7W@yuanjiey.ap.qualcomm.com/ > > This values is according to the NT37801 panel sec > "The NT37801 Sepc V1.0 chapter "5.7.1 Power On Sequence" states > VDDI=1.65V~1.95V." > Yes, so the panel requires 1.65V, so regulator-min-microvolt needs to be at least that. But regulator-min-microvolt should account for all the consumers of the rail, are there any others? Which leads me to my question, the people designing the board named the rail VREG_L12B_1P8 in the schematics, why didn't they name it VREG_L12B_1P65? Please check all the consumers and make the regulator-min-microvolt work for all of them - if that's 1.65V, then your change is good. Regards, Bjorn > Thanks, > Ayushi > > >> regulator-max-microvolt = <1800000>; > >> regulator-initial-mode = ; > >> regulator-allow-set-load; > >> -- > >> 2.34.1 > >> >