From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B97991D90A2 for ; Fri, 25 Oct 2024 10:03:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729850624; cv=none; b=d0sgn5MMotsppBJV4ErJDZbro2GF5fFtW8ImJ4XdE0vK6avEiuxOQVeofciEC2+LheNnEGPvgNQ8UeHUbd28dEZlpCjNIIZN5f2rbEUps+ryMDRpqURivH9UE5V7KCJ3LNsLe8jImD9tyffaNrcIPQQpZxcmWc+qTuSLX8tBt18= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729850624; c=relaxed/simple; bh=5P5MFcEdDSRIGAl3+cjMSXO4SCdJPWExSWKV2maR55w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qOb2TW1+ynqg2/KX7MJKygxaZnQRlCnXGCF7RX9AsK/2pClP63IRRoydOCNPWIkW9gJp2/Ae3fvAUOEuX01ycrfBseGTGfZVbPeENxMxXV4g5gSZNlqrHhQg2aL012FVNEP3FDbggPkIZ4dIrYrHeYxiyUuhqKxDSR/16q8K+Hs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B36B1339; Fri, 25 Oct 2024 03:04:11 -0700 (PDT) Received: from [10.1.36.18] (e122027.cambridge.arm.com [10.1.36.18]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A064A3F73B; Fri, 25 Oct 2024 03:03:39 -0700 (PDT) Message-ID: <5673689c-28cd-4fc5-a627-4858ebe9face@arm.com> Date: Fri, 25 Oct 2024 11:03:35 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] drm/panthor: Explicitly set the coherency mode To: Akash Goel , boris.brezillon@collabora.com, liviu.dudau@arm.com Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, mihail.atanassov@arm.com, ketil.johnsen@arm.com, florent.tomasin@arm.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, nd@arm.com References: <20241024145432.934086-1-akash.goel@arm.com> <20241024145432.934086-3-akash.goel@arm.com> From: Steven Price Content-Language: en-GB In-Reply-To: <20241024145432.934086-3-akash.goel@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 24/10/2024 15:54, Akash Goel wrote: > This commit fixes the potential misalignment between the value of device > tree property "dma-coherent" and default value of COHERENCY_ENABLE > register. > Panthor driver didn't explicitly program the COHERENCY_ENABLE register > with the desired coherency mode. The default value of COHERENCY_ENABLE > register is implementation defined, so it may not be always aligned with > the "dma-coherent" property value. > The commit also checks the COHERENCY_FEATURES register to confirm that > the coherency protocol is actually supported or not. > > Signed-off-by: Akash Goel Reviewed-by: Steven Price > --- > drivers/gpu/drm/panthor/panthor_device.c | 22 +++++++++++++++++++++- > drivers/gpu/drm/panthor/panthor_gpu.c | 9 +++++++++ > 2 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c > index 4082c8f2951d..984615f4ed27 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.c > +++ b/drivers/gpu/drm/panthor/panthor_device.c > @@ -22,6 +22,24 @@ > #include "panthor_regs.h" > #include "panthor_sched.h" > > +static int panthor_gpu_coherency_init(struct panthor_device *ptdev) > +{ > + ptdev->coherent = device_get_dma_attr(ptdev->base.dev) == DEV_DMA_COHERENT; > + > + if (!ptdev->coherent) > + return 0; > + > + /* Check if the ACE-Lite coherency protocol is actually supported by the GPU. > + * ACE protocol has never been supported for command stream frontend GPUs. > + */ > + if ((gpu_read(ptdev, GPU_COHERENCY_FEATURES) & > + GPU_COHERENCY_PROT_BIT(ACE_LITE))) > + return 0; > + > + drm_err(&ptdev->base, "Coherency not supported by the device"); > + return -ENOTSUPP; > +} > + > static int panthor_clk_init(struct panthor_device *ptdev) > { > ptdev->clks.core = devm_clk_get(ptdev->base.dev, NULL); > @@ -156,7 +174,9 @@ int panthor_device_init(struct panthor_device *ptdev) > struct page *p; > int ret; > > - ptdev->coherent = device_get_dma_attr(ptdev->base.dev) == DEV_DMA_COHERENT; > + ret = panthor_gpu_coherency_init(ptdev); > + if (ret) > + return ret; > > init_completion(&ptdev->unplug.done); > ret = drmm_mutex_init(&ptdev->base, &ptdev->unplug.lock); > diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c > index 5251d8764e7d..1e24f08a519a 100644 > --- a/drivers/gpu/drm/panthor/panthor_gpu.c > +++ b/drivers/gpu/drm/panthor/panthor_gpu.c > @@ -77,6 +77,12 @@ static const struct panthor_model gpu_models[] = { > GPU_IRQ_RESET_COMPLETED | \ > GPU_IRQ_CLEAN_CACHES_COMPLETED) > > +static void panthor_gpu_coherency_set(struct panthor_device *ptdev) > +{ > + gpu_write(ptdev, GPU_COHERENCY_PROTOCOL, > + ptdev->coherent ? GPU_COHERENCY_PROT_BIT(ACE_LITE) : GPU_COHERENCY_NONE); > +} > + > static void panthor_gpu_init_info(struct panthor_device *ptdev) > { > const struct panthor_model *model; > @@ -365,6 +371,9 @@ int panthor_gpu_l2_power_on(struct panthor_device *ptdev) > hweight64(ptdev->gpu_info.shader_present)); > } > > + /* Set the desired coherency mode before the power up of L2 */ > + panthor_gpu_coherency_set(ptdev); > + > return panthor_gpu_power_on(ptdev, L2, 1, 20000); > } >