From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B06E3A9D8B for ; Wed, 29 Jul 2026 06:22:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785306176; cv=pass; b=qr6lsto+ALe+3jOyPX6eczMK+F6AoMLfwfifsZgEwrKepKjIkzxXOONf5j2+xQvJxkAAianQH4clOxnH23e/YRKNvLK409lWYl4dDdHoNr0EPgLa6Y2BLc6V5CJLM19AYC1wG0nEP2ykIJls/WWGgPQxx3DO/3vVwZOJP90sduk= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785306176; c=relaxed/simple; bh=vvXYkDBuD2KLDTbwC9pa5bOfWhqNLZrp1WaeNv5Yb/A=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=pLKcI3a23O/05wL1qH6rRJSs9YzoMhIm8eLkBJLRneWP8fUbKRX5/NPXlPozJRq1dgy7ZCRIpognhhXGQGPP1PPhrOmN420KaIR21QEp2rrYbNHH5V14bGs5XnWM4Lc5L+YGa+luSqPQ6BYlJArbs2ubP+R9nJC240RdZD+/Gjw= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b=CEDGyZxp; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=nicolas.frattaroli@collabora.com header.b="CEDGyZxp" ARC-Seal: i=1; a=rsa-sha256; t=1785306010; cv=none; d=zohomail.com; s=zohoarc; b=SxENcy4tAWPxuWcNsnzQZy+NRXukQck1HEgibJdYohf5+GOXWjJzdD4vgWq0vj/Mo23/o98LSN+4/bnRfLjkRPHB8vEcqtXE/rH/rpfJ/+Xs5/NtVW/yZRVdhbRla1s3mNAtZsKKk5YCF/H84Zdl5PbF1x6RSNJnufccR5NK9MM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1785306010; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=LcPy/OklKjXHhgvBvBHEu3COEFzG3JBaEkM4/MoUaTE=; b=Ulp58vzVpnn/U5S6ERm1Ffn/n0y+SdYub/vXCKr4UNNiodDTqvskVS+mdoTnzeDqnUbPjDvafo0jt4itCHcpDlqVWo4Iy2y2u+xvJGdxCdj22S6Yee+bD/rZK+sRri85w85SNgiuB5nGcM16iusvJqSAv/kWnjcDV22qJ7xPYHM= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=nicolas.frattaroli@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1785306010; s=zohomail; d=collabora.com; i=nicolas.frattaroli@collabora.com; h=From:From:Subject:Subject:Date:Date:Message-Id:Message-Id:MIME-Version:Content-Type:Content-Transfer-Encoding:To:To:Cc:Cc:Reply-To; bh=LcPy/OklKjXHhgvBvBHEu3COEFzG3JBaEkM4/MoUaTE=; b=CEDGyZxpEA3OY7CQut62GIFC1HbN2zo2berK78ebV1ydLX3T+3I0YU6k0Y2BJ/od FuUlGKIcu8FaD9DxV31i+LbCnxIGKpb2or2djF9Hb8UgBkSviCn+N304+/k+gWM0G6Y 4rh3EX29+lQr2HWmRpYPKlL7vZ7urtHuPXfYyQQM= Received: by mx.zohomail.com with SMTPS id 1785306008697356.1189702710186; Tue, 28 Jul 2026 23:20:08 -0700 (PDT) From: Nicolas Frattaroli Subject: [PATCH 0/3] Rework panthor's cache flush and soft reset locking Date: Wed, 29 Jul 2026 08:19:48 +0200 Message-Id: <20260729-panthor-cache-flush-fix-v1-0-205921ed3c81@collabora.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/y2NTQ6CMBCFr9LM2olQIipXMSzaYbBjLGBbjAnh7 lZh9fK9vJ8FIgfhCI1aIPBbooxDhvKggJwZ7ozSZQZd6Lo46wtOZkhuDEiGHGP/nKPDXj5oq5p seeqvmirI7Slwtv/Lt3bjONsHU/rN7YnArzlfpi0G1kRGGr2X1KgueEwyHXeFdl2/VC+/Za4AA AA= X-Change-ID: 20260728-panthor-cache-flush-fix-b36cb15f92c3 To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Boris Brezillon , Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Grant Likely , Heiko Stuebner Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, kernel@collabora.com, Nicolas Frattaroli X-Mailer: b4 0.15.2 There are two problems in panthor's cache flushing/soft reset code related to locking. The first problem is that the spinlocks are taken with _irqsave, even though the contended lock is never acquired in a raw interrupt handler. Only a threaded handler locks it. The second problem is that the wait_event condition references pending_reqs without holding the required lock. This means there's a data race. While resolving the first problem is easy, the second problem requires adding some more macro variants to wait.h, which is done in the first patch. New tracepoints to debug cache flushing duration without initial locking waits is thrown in for good measure as well, to complement what's in lock_stat and what the function tracer can already do. Signed-off-by: Nicolas Frattaroli --- Nicolas Frattaroli (3): wait: Introduce non-irq variants of wait_event_lock_timeout drm/panthor: Revisit reqs_lock handling in flush/reset paths drm/panthor: Add tracepoints for cache flushing drivers/gpu/drm/panthor/panthor_gpu.c | 28 +++++------ drivers/gpu/drm/panthor/panthor_trace.h | 58 +++++++++++++++++++++++ include/linux/wait.h | 84 +++++++++++++++++++++++++++++++++ 3 files changed, 156 insertions(+), 14 deletions(-) --- base-commit: f57436380d5de1c1ded898e21378b0b4159c8790 change-id: 20260728-panthor-cache-flush-fix-b36cb15f92c3 Best regards, -- Nicolas Frattaroli