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 AEF39C77B7C for ; Thu, 3 Jul 2025 10:02:21 +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-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=MRfjg5TqBCi/KJ5DoNhO/Uetad51xuSqQDeNpXClAuE=; b=viZTG5XaPx1qUzX/635iBUOxHJ MEMzFX2ZUYUGBmEj0jy12g59VzCCLLc53Je2aZoMnbKSjYGTLn2iIKKYgSKyt51KmDEM/kzHTZrJH +GnE/PUtX98t5QBokBbm/3S6/tfcgo9hmdDK3cyLTXrsyAS2d9qhpqK6MMF3TSVmjyhzIMUkIdhll ItvPxYZaoC7FzUwWFQummv/W4AoTF8mn92Jlk9BhaY9frHjUZ6vAND+5xQCEMfyrS9FrKWYCxY9dG HniACGoxH1dvSOu1mXNeO/R2Yj3GmvdDLwt8lfBVG1Swo8xBYgyNb6EqhYS3WMW99zJRYhxuC38ac rKEcYw2A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uXGlj-0000000AvFW-2jjl; Thu, 03 Jul 2025 10:02:15 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uXGh3-0000000AuX7-3O8U for linux-arm-kernel@lists.infradead.org; Thu, 03 Jul 2025 09:57:27 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1uXGgb-0007Za-5y; Thu, 03 Jul 2025 11:56:57 +0200 Message-ID: <8db56c73-191e-48ec-9a28-cbb0da9a8a80@pengutronix.de> Date: Thu, 3 Jul 2025 11:56:56 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 0/6] imx8mp: add support for the IMX AIPSTZ bridge To: Laurentiu Mihalcea , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Shawn Guo , Sascha Hauer , Fabio Estevam , Daniel Baluta , Shengjiu Wang , Frank Li , Marco Felsch , Marc Kleine-Budde , Alexander Stein Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Pengutronix Kernel Team , imx@lists.linux.dev References: <20250610160152.1113930-1-laurentiumihalcea111@gmail.com> <3615415b-7ebd-45e5-8d7b-8a1b26ac7130@pengutronix.de> <10ef8a9a-6d23-4fb9-933f-71ab493d21c7@gmail.com> Content-Language: en-US, de-DE, de-BE From: Ahmad Fatoum In-Reply-To: <10ef8a9a-6d23-4fb9-933f-71ab493d21c7@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250703_025725_848527_FC5570FB X-CRM114-Status: GOOD ( 21.35 ) 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 Hello Laurentiu, On 7/3/25 10:51, Laurentiu Mihalcea wrote: > > > On 7/3/2025 11:11 AM, Ahmad Fatoum wrote: >> Hello Laurentiu, >> >> On 10.06.25 18:01, Laurentiu Mihalcea wrote: >>> From: Laurentiu Mihalcea >>> >>> The AIPSTZ bridge offers some security-related configurations which can >>> be used to restrict master access to certain peripherals on the bridge. >>> >>> Normally, this could be done from a secure environment such as ATF before >>> Linux boots but the configuration of AIPSTZ5 is lost each time the power >>> domain is powered off and then powered on. Because of this, it has to be >>> configured each time the power domain is turned on and before any master >>> tries to access the peripherals (e.g: AP, CM7, DSP, on i.MX8MP). >> Sorry if this has been asked before, but I hoped the cover letter or patch >> 3/6 would explain if it were. >> >> What is the default configuration for the AIPSTZ before this series? > > the default configuration is the reset configuration since AIPSTZ registers go > back to their reset values during domain power cycling. > >> I assume the SAIs under AIPS5 can be accessed by SDMA already, so why was >> changing the AIPSTZ settings needed for the DSP to work? > > AFAIK SDMA transactions to peripherals don't go through AIPS5. They use SPBA, which > is why SDMA works even w/o this series. As for the DSP: transactions to peripherals go > through AIPS5. With the reset configuration, the DSP is not allowed to access said peripherals, > which is why this series was needed. I see. Thanks for tackling this issue and your explanation. Cheers, Ahmad > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |