From patchwork Thu Aug 29 13:05:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ma=C3=ADra_Canal?= X-Patchwork-Id: 13783181 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 49D1FC83F16 for ; Thu, 29 Aug 2024 13:10:49 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C9D4710E672; Thu, 29 Aug 2024 13:10:48 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.b="hchl26yh"; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id DB08710E05D for ; Thu, 29 Aug 2024 13:10:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=rJVKjv1l2kixDycjzD1h3vu8/tY7RY+hri4oItX+an0=; b=hchl26yhVXd2FvVYpUBP53TZ4y MfjybCyKWPnTb4EWqsHABzz6vpUsX1FIZMaQXp/KiI/PiqvRgTQhKIOmoKIroE+KkZOptMF5FGva1 n3Y5YHC5LhhYLahtEBXW31HHVkeVxCEkaEK42CBT3weM4HQd2qVuKxSvS61IWP+Vy1a0xke9VPvki iY1SZjjrg1LDk5eKcIio395ipZhM1bXCH3xCFFgAs6Cr42FfV9QfgN04PVxxmTw1HQS4ncAzuovFl qhECGjFwoUOW3KqwUXBcRdcb5ORN80Gewwqm5pYrzEKUOQYjyotToSqvxq+UImmvoEgIYP6dWdjvX 7i2NcB/Q==; Received: from [187.36.213.55] (helo=morissey..) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1sjev6-006jlG-FB; Thu, 29 Aug 2024 15:10:36 +0200 From: =?utf-8?q?Ma=C3=ADra_Canal?= To: Melissa Wen , Iago Toral , Tvrtko Ursulin , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, kernel-dev@igalia.com, =?utf-8?q?Ma?= =?utf-8?q?=C3=ADra_Canal?= Subject: [PATCH v5 01/10] drm/v3d: Fix the MMU flush order Date: Thu, 29 Aug 2024 10:05:09 -0300 Message-ID: <20240829130954.2439316-2-mcanal@igalia.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240829130954.2439316-1-mcanal@igalia.com> References: <20240829130954.2439316-1-mcanal@igalia.com> MIME-Version: 1.0 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" We must first flush the MMU cache and then, flush the TLB, not the other way around. Currently, we can see a race condition between the MMU cache and the TLB when running multiple rendering processes at the same time. This is evidenced by MMU errors triggered by the IRQ. Fix the MMU flush order by flushing the MMU cache and then the TLB. Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+") Signed-off-by: Maíra Canal --- drivers/gpu/drm/v3d/v3d_mmu.c | 29 ++++++++++------------------- 1 file changed, 10 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/v3d/v3d_mmu.c b/drivers/gpu/drm/v3d/v3d_mmu.c index 14f3af40d6f6..06bb44c7f35d 100644 --- a/drivers/gpu/drm/v3d/v3d_mmu.c +++ b/drivers/gpu/drm/v3d/v3d_mmu.c @@ -32,32 +32,23 @@ static int v3d_mmu_flush_all(struct v3d_dev *v3d) { int ret; - /* Make sure that another flush isn't already running when we - * start this one. - */ - ret = wait_for(!(V3D_READ(V3D_MMU_CTL) & - V3D_MMU_CTL_TLB_CLEARING), 100); - if (ret) - dev_err(v3d->drm.dev, "TLB clear wait idle pre-wait failed\n"); - - V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL) | - V3D_MMU_CTL_TLB_CLEAR); - - V3D_WRITE(V3D_MMUC_CONTROL, - V3D_MMUC_CONTROL_FLUSH | + V3D_WRITE(V3D_MMUC_CONTROL, V3D_MMUC_CONTROL_FLUSH | V3D_MMUC_CONTROL_ENABLE); - ret = wait_for(!(V3D_READ(V3D_MMU_CTL) & - V3D_MMU_CTL_TLB_CLEARING), 100); + ret = wait_for(!(V3D_READ(V3D_MMUC_CONTROL) & + V3D_MMUC_CONTROL_FLUSHING), 100); if (ret) { - dev_err(v3d->drm.dev, "TLB clear wait idle failed\n"); + dev_err(v3d->drm.dev, "MMUC flush wait idle failed\n"); return ret; } - ret = wait_for(!(V3D_READ(V3D_MMUC_CONTROL) & - V3D_MMUC_CONTROL_FLUSHING), 100); + V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL) | + V3D_MMU_CTL_TLB_CLEAR); + + ret = wait_for(!(V3D_READ(V3D_MMU_CTL) & + V3D_MMU_CTL_TLB_CLEARING), 100); if (ret) - dev_err(v3d->drm.dev, "MMUC flush wait idle failed\n"); + dev_err(v3d->drm.dev, "TLB clear wait idle failed\n"); return ret; }