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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7032C25B06 for ; Thu, 11 Aug 2022 16:24:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238005AbiHKQYN (ORCPT ); Thu, 11 Aug 2022 12:24:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237905AbiHKQXg (ORCPT ); Thu, 11 Aug 2022 12:23:36 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3207A1A48; Thu, 11 Aug 2022 09:04:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 68F98B821AD; Thu, 11 Aug 2022 16:04:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10E25C433D6; Thu, 11 Aug 2022 16:04:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660233879; bh=KtU1UXw97w/H2xLkM6zY7iXR0EZy+lQMFV02YeRNmbw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZicX6KENB3D9loI90DIoxVSbR3y20eqg5KmFY6BgrRj1u4C/4qJujGrQl58YMziuV NFUP4S62X/IzmqU6sSIm86UR+pgZzjltcDGfcHgn8dQL5zFQosrk4n1TMC5UKqZXuf YCRC1tLN/Ryhsqtc1XaITWMCSQsH3KCqOhcVVBes+a3x+ENgIcNHiQksTkDvnDk3zU PnBbYhvXIWMJbQX9y/kB/qnLaUc/Ao2qfajZAkm59LaQr5qa+fVzqSxjtpgqp6z1j2 88KilIZQWVwAWPvdWe/I8YJB84g1RKH8EuVsfqhWV2marA8aJ/H0wUWZsknSf5/Z0d DhKddKJgTh4QA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Alyssa Rosenzweig , Steven Price , Sasha Levin , robh@kernel.org, tomeu.vizoso@collabora.com, airlied@linux.ie, daniel@ffwll.ch, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.10 06/46] drm/panfrost: Don't set L2_MMU_CONFIG quirks Date: Thu, 11 Aug 2022 12:03:30 -0400 Message-Id: <20220811160421.1539956-6-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811160421.1539956-1-sashal@kernel.org> References: <20220811160421.1539956-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alyssa Rosenzweig [ Upstream commit d8e53d8a4e0ae842ef5e83e0dfb0796980f710cf ] L2_MMU_CONFIG is an implementation-defined register. Different Mali GPUs define slightly different MAX_READS and MAX_WRITES fields, which throttle outstanding reads and writes when set to non-zero values. When left as zero, reads and writes are not throttled. Both kbase and panfrost always zero these registers. Per discussion with Steven Price, there are two reasons these quirks may be used: 1. Simulating slower memory subsystems. This use case is only of interest to system-on-chip designers; it is not relevant to mainline. 2. Working around broken memory subsystems. Hopefully we never see this case in mainline. If we do, we'll need to set this register based on an SoC-compatible, rather than generally matching on the GPU model. To the best of our knowledge, these fields are zero at reset, so the write is not necessary. Let's remove the write to aid porting to new Mali GPUs, which have different layouts for the L2_MMU_CONFIG register. Suggested-by: Steven Price Reviewed-by: Steven Price Signed-off-by: Alyssa Rosenzweig Link: https://patchwork.freedesktop.org/patch/msgid/20220525145754.25866-8-alyssa.rosenzweig@collabora.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/panfrost/panfrost_gpu.c | 12 ------------ 1 file changed, 12 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c index d22bb2589cb1..ce310b4496d8 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c @@ -127,18 +127,6 @@ static void panfrost_gpu_init_quirks(struct panfrost_device *pfdev) gpu_write(pfdev, GPU_TILER_CONFIG, quirks); - quirks = gpu_read(pfdev, GPU_L2_MMU_CONFIG); - - /* Limit read & write ID width for AXI */ - if (panfrost_has_hw_feature(pfdev, HW_FEATURE_3BIT_EXT_RW_L2_MMU_CONFIG)) - quirks &= ~(L2_MMU_CONFIG_3BIT_LIMIT_EXTERNAL_READS | - L2_MMU_CONFIG_3BIT_LIMIT_EXTERNAL_WRITES); - else - quirks &= ~(L2_MMU_CONFIG_LIMIT_EXTERNAL_READS | - L2_MMU_CONFIG_LIMIT_EXTERNAL_WRITES); - - gpu_write(pfdev, GPU_L2_MMU_CONFIG, quirks); - quirks = 0; if ((panfrost_model_eq(pfdev, 0x860) || panfrost_model_eq(pfdev, 0x880)) && pfdev->features.revision >= 0x2000) -- 2.35.1