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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2B48C4338F for ; Mon, 23 Aug 2021 21:14:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A7216613A6 for ; Mon, 23 Aug 2021 21:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232798AbhHWVOs (ORCPT ); Mon, 23 Aug 2021 17:14:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232710AbhHWVOl (ORCPT ); Mon, 23 Aug 2021 17:14:41 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C65B7C061575; Mon, 23 Aug 2021 14:13:57 -0700 (PDT) Received: from maud (unknown [IPv6:2600:8800:8c06:1000::c8f3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: alyssa) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 957661F42654; Mon, 23 Aug 2021 22:13:52 +0100 (BST) Date: Mon, 23 Aug 2021 17:13:45 -0400 From: Alyssa Rosenzweig To: Steven Price Cc: Alyssa Rosenzweig , dri-devel@lists.freedesktop.org, Rob Herring , Tomeu Vizoso , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org, Chris Morgan , stable@vger.kernel.org Subject: Re: [PATCH 3/3] drm/panfrost: Clamp lock region to Bifrost minimum Message-ID: References: <20210820213117.13050-1-alyssa.rosenzweig@collabora.com> <20210820213117.13050-4-alyssa.rosenzweig@collabora.com> <818b1a15-ddf4-461b-1d6a-cea539deaf76@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <818b1a15-ddf4-461b-1d6a-cea539deaf76@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > When locking a region, we currently clamp to a PAGE_SIZE as the minimum > > lock region. While this is valid for Midgard, it is invalid for Bifrost, > > While the spec does seem to state it's invalid for Bifrost - kbase > didn't bother with a lower clamp for a long time. I actually think this > is in many ways more of a spec bug: i.e. implementation details of the > round-up that the hardware does. But it's much safer following the spec > ;) And it seems like kbase eventually caught up too. Yeah, makes sense. Should I drop the Cc: stable in that case? If the issue is purely theoretical.