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 508D3D1950F for ; Mon, 26 Jan 2026 20:10:58 +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:Content-Type: Content-Transfer-Encoding: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=Is3I+8ssoS9D+BYoCg1mTA9PvtKWkCtdZPek/z/LAa0=; b=V5ymxOf1SZQ+X/3blH4NplExp+ cilrvltOdbj1Nh6ZBawEM+kNn4fMwoKU2BNpu8PbYMedL3jCo9O8yKBrVcAeUbX21AcU/0wXHrHnS tjlx273yI/nzxVhPAG8VTCXfJIkQvFUdrFmh7oK5zWHbd0t4kYlhMfcwWLcvMdWlx9Bv2b4OAmln6 2XyfMXitmHOTiJJpo8ePbhUxxCFHml8u9EZvP2L7fgoBID4aU1e6+9v8eYaOGAEqGvXFRNz/fgWgY IM2PbpFctLRQkfb8ip0z4msUvNItqr7lMCCMy1zh0XyfJa3dNtwt9q4WjSn7gN0+oXprNL8wONI/D +SIY0TtA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vkSv9-0000000DBAe-300E; Mon, 26 Jan 2026 20:10:47 +0000 Received: from ms.puri.sm ([135.181.196.210]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vkSv7-0000000DBAC-1Lm8 for linux-arm-kernel@lists.infradead.org; Mon, 26 Jan 2026 20:10:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=puri.sm; s=smtp2; t=1769458239; bh=RdybJ+RhItlzNNAOTr267+9hICGF7MXvJl8utG+MmF4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KpLjCTddhsijq2oEtM+wJOTd6g9VSp70CIHBiklKsuY/lV5vPz4nxyzcz1wsI+NoI 1dIM+2hyjS2yUM+URsz9rXOwoY+wIQ6VhqezQwh+rN8Vuq1oZhAVEMRLTI9GEC6PZl 2QPW8GAyKxLqc44ar3zZW5W0o7xqHS3NOoOKKF5lvyogEi+X+EhKGWqd/DHWyo7Yxt UYxnL1ciWY7KO9X3L4Yofht+AgwEGXzt/XIK+dze8WRUgqT8yH51gwvsFLLxtAmwjj ZfN7hjhSJgfMgfskQT9Nxso/KmkVQQlf9JXmzN9JKtlHr9POMAnIEXISXbTIYmQ5DW XULQEnq2sdcWQ== Received: from pliszka.localnet (79.184.64.12.ipv4.supernova.orange.pl [79.184.64.12]) by ms.puri.sm (Postfix) with ESMTPSA id 10A8C1FA2D; Mon, 26 Jan 2026 12:10:39 -0800 (PST) From: Sebastian Krzyszkowiak To: Frank Li Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@puri.sm Subject: Re: [PATCH] arm64: dts: imx8mq: Set the correct gpu_ahb clock frequency Date: Mon, 26 Jan 2026 21:10:37 +0100 Message-ID: <8657865.DvuYhMxLoT@pliszka> In-Reply-To: References: <20260124-imx8mq-gpu-ahb-clock-v1-1-11c2e7c857b7@puri.sm> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260126_121045_524118_59FC8556 X-CRM114-Status: GOOD ( 18.30 ) 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 poniedzia=C5=82ek, 26 stycznia 2026 19:14:55 czas =C5=9Brodkowoeuropejsk= i standardowy=20 =46rank Li wrote: > On Sat, Jan 24, 2026 at 02:55:48PM +0100, Sebastian Krzyszkowiak wrote: > > According to i.MX 8M Quad Reference Manual, GPU_AHB_CLK_ROOT's maximum > > frequency is 400MHz. >=20 > I checked datasheet >=20 > Nominal mode=E2=80=94the maximum > GPU frequency supported in > this mode is 800 MHz. >=20 > Does difference grade (industry vs consumer) impact max frequency? No. That sentence relates to GPU_SHADER_CLK_ROOT, which can go up to 1000 M= Hz,=20 but requires "overdrive mode" (higher voltage) when above 800 MHz. It's set= to=20 800 MHz in the device tree at the moment. This patch changes GPU_AHB_CLK_ROOT, which has absolute maximum of 400 MHz= =20 (see section 5.1.2 Table 5-1). > Frank >=20 > > Signed-off-by: Sebastian Krzyszkowiak > > --- > >=20 > > arch/arm64/boot/dts/freescale/imx8mq.dtsi | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > >=20 > > diff --git a/arch/arm64/boot/dts/freescale/imx8mq.dtsi > > b/arch/arm64/boot/dts/freescale/imx8mq.dtsi index > > 607962f807be..6a25e219832c 100644 > > --- a/arch/arm64/boot/dts/freescale/imx8mq.dtsi > > +++ b/arch/arm64/boot/dts/freescale/imx8mq.dtsi > > @@ -1632,7 +1632,7 @@ gpu: gpu@38000000 { > >=20 > > <&clk=20 IMX8MQ_GPU_PLL_OUT>, > > <&clk=20 IMX8MQ_GPU_PLL>; > > =09 > > assigned-clock-rates =3D <800000000>,=20 <800000000>, > >=20 > > - <800000000>,=20 <800000000>, <0>; > > + <800000000>,=20 <400000000>, <0>; > >=20 > > power-domains =3D <&pgc_gpu>; > > =09 > > }; > >=20 > > --- > > base-commit: 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7 > > change-id: 20260105-imx8mq-gpu-ahb-clock-139ba9ca9a6c > >=20 > > Best regards, > > -- > > Sebastian Krzyszkowiak