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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 3B0B6CD4F24 for ; Tue, 12 May 2026 15:38:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9954810E26D; Tue, 12 May 2026 15:38:47 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=arm.com header.i=@arm.com header.b="atLEN8zi"; dkim-atps=neutral Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 8DB9E10E26D for ; Tue, 12 May 2026 15:38:45 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AA399202C for ; Tue, 12 May 2026 08:38:39 -0700 (PDT) Received: from [192.168.0.1] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9F23B3F85F for ; Tue, 12 May 2026 08:38:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778600324; bh=bTW8PIkNq6aZUF6NF1FmasGVCIC4HDNHJXMvlerQOQM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=atLEN8zitquJu3MG2aDl/Vqi6TIEMDlsKtSGYcLkHaOfl4AHGPBij+gXG69ChKKYd ijqGR2Ve35H7L3fyGUjrh7DWwjYtUcWBrcRFp8tvLqWE5Oax9UyGR45UTiyHML5BEr d5ibpUQ7gS9C9zwyUwCXCD9joyVUtQFxO65pgXZI= Date: Tue, 12 May 2026 16:38:18 +0100 From: Liviu Dudau To: Boris Brezillon Cc: Marcin =?utf-8?Q?=C5=9Alusarz?= , Ketil Johnsen , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Jonathan Corbet , Shuah Khan , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , Christian =?utf-8?B?S8O2bmln?= , Steven Price , Daniel Almeida , Alice Ryhl , Matthias Brugger , AngeloGioacchino Del Regno , dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Florent Tomasin , nd@arm.com Subject: Re: [PATCH 4/8] drm/panthor: Add support for protected memory allocation in panthor Message-ID: References: <20260505140516.1372388-1-ketil.johnsen@arm.com> <20260505140516.1372388-5-ketil.johnsen@arm.com> <20260505181523.49a3d85c@fedora> <20260507135356.5428d50d@fedora> <20260512161111.0cb7000e@fedora> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260512161111.0cb7000e@fedora> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Tue, May 12, 2026 at 04:11:11PM +0200, Boris Brezillon wrote: > On Tue, 12 May 2026 14:47:27 +0100 > Liviu Dudau wrote: > > > On Thu, May 07, 2026 at 01:53:56PM +0200, Boris Brezillon wrote: > > > On Thu, 7 May 2026 11:02:26 +0200 > > > Marcin Ślusarz wrote: > > > > > > > On Tue, May 05, 2026 at 06:15:23PM +0200, Boris Brezillon wrote: > > > > > > @@ -277,9 +286,21 @@ int panthor_device_init(struct panthor_device *ptdev) > > > > > > return ret; > > > > > > } > > > > > > > > > > > > + /* If a protected heap name is specified but not found, defer the probe until created */ > > > > > > + if (protected_heap_name && strlen(protected_heap_name)) { > > > > > > > > > > Do we really need this strlen() > 0? Won't dma_heap_find() fail is the > > > > > name is "" already? > > > > > > > > If dma_heap_find() will fail, then the whole probe with fail too. > > > > This check prevents that. > > > > > > Yeah, that's also a questionable design choice. I mean, we can > > > currently probe and boot the FW even though we never setup the > > > protected FW sections, so why should we defer the probe here? Can't we > > > just retry the next time a group with the protected bit is created and > > > fail if we can find a protected heap? > > > > The problem we have with the current firmware is that it does a number of setup steps at "boot" > > time only. One of the steps is preparing its internal structures for when it enters protected > > mode and it stores them in the buffer passed in at firmware loading. We cannot later run the > > process when we have a group with protected mode set. > > No, but we can force a full/slow reset and have that thing > re-initialized, can't we? I mean, that's basically what we do when a > fast reset fails: we re-initialize all the sections and reset again, at > which point the FW should start from a fresh state, and be able to > properly initialize the protected-related stuff if protected sections > are populated. Am I missing something? Right, we can do that. For some reason I keep associating the reset with the error handling and not with "normal" operations. Best regards, Liviu -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯