From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 558AA2E975E for ; Tue, 1 Sep 2026 13:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788269861; cv=none; b=Eg8X9SLTeYC/H9zIvb539pfqWknDtlXcaa8lzpp9kKd1XoxcaQ1RoZYi1/o2Qb3w5JEBqwoF5gMJT+UKePtI1w/Bha46WPftSfNgZ+02aVzWxo29OgHUhz8hRPUUcx+j66+lXGyXgZFiAjwYZc/RrdS/7HPyjF5vj7ohDlEPdKw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788269861; c=relaxed/simple; bh=zDlfCbDH5Ho3SI3QsSZnX/Jgy1GCPpw11VZy6Ij11kU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JFbKv3L4KxgabIEzCGD5WbSgxhVM0d9yxPBtjkLk+rcF5Y6fm0IgKJ0MI/FJIbYpsMF1Hw3afZaiCQ187sNnqpSbxTQHd4IFJYvZSY/Pe6MzNUxw0uSkMTHXODq4elUBGpj7og/9tPiVPmqROx5JNkNBllt+N2ejKOtdLLzmFUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=XddVYdRY; arc=none smtp.client-ip=148.251.105.195 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 (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="XddVYdRY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1788269858; bh=zDlfCbDH5Ho3SI3QsSZnX/Jgy1GCPpw11VZy6Ij11kU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XddVYdRYJFykaXV1kzy0zskkljn/S2TIWbGpeDB9MDz9vQI51T7aVCbMRVOBxwwSL VGVDE1qg/fM5Q6lhvbzPJJicorRPSo6VT6Dzj+snvZ0w5K7fKeWFieTx7kWkm8P6xS NYH5EY0X5Iuon++Kdz1YwfQ4yaLWo/T9xB0q/m/5ExVvjwTfRklCf9TXmcOEhWRtuo A6ZyRJ0OkRFrboem8IUzWQjvBeTE8TewmVLRdcju37OKDp/O5Fp2NhIVxmYDZNdvLE MnsAf6JrHZdBBLtU0RcSQAtWAhiGi+SJUH1DWGBKggrMRICybaWcElo/ZZfkmoPCPZ v1o+2eoZsphnw== Received: from fedora-21.home (unknown [100.64.0.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id BBA1917E006A; Tue, 01 Sep 2026 15:37:37 +0200 (CEST) Date: Tue, 1 Sep 2026 15:37:32 +0200 From: Boris Brezillon To: =?UTF-8?B?QWRyacOhbg==?= Larumbe Cc: Rob Herring , Steven Price , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Faith Ekstrand , "Marty E. Plummer" , Tomeu Vizoso , Eric Anholt , Alyssa Rosenzweig , Robin Murphy , Philipp Zabel , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Collabora Kernel Team , Neil Armstrong Subject: Re: [PATCH v7 14/17] drm/panfrost: Avoid cache flush after perfcnt sample in fully coherent systems Message-ID: <20260901153732.7c4def61@fedora-21.home> In-Reply-To: <20260828-claude-fixes-v7-14-72a13b2c125d@collabora.com> References: <20260828-claude-fixes-v7-0-72a13b2c125d@collabora.com> <20260828-claude-fixes-v7-14-72a13b2c125d@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-linux-gnu) 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: quoted-printable On Fri, 28 Aug 2026 21:56:54 +0100 Adri=C3=A1n Larumbe wrote: > If the GPU and CPU are fully coherent, then there's no need to flush the > GPU caches after a perfcnt sample is made available. >=20 > Signed-off-by: Adri=C3=A1n Larumbe > --- > drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) >=20 > diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/dr= m/panfrost/panfrost_perfcnt.c > index ffc77121070e..b3f71d7fd82a 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > +++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c > @@ -52,7 +52,10 @@ void panfrost_perfcnt_clean_cache_done(struct panfrost= _device *pfdev) > =20 > void panfrost_perfcnt_sample_done(struct panfrost_device *pfdev) > { > - gpu_write(pfdev, GPU_CMD, GPU_CMD_CLEAN_CACHES); > + if (pfdev->features.selected_coherency !=3D COHERENCY_ACE) I think ACE_LITE would allow us to skip the flush to, so if (pfdev->features.selected_coherency =3D=3D COHERENCY_NONE) > + gpu_write(pfdev, GPU_CMD, GPU_CMD_CLEAN_CACHES); > + else > + complete(&pfdev->perfcnt->dump_comp); > } > =20 > static int panfrost_perfcnt_dump_locked(struct panfrost_device *pfdev) >=20