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 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 EF57CC5DF81 for ; Wed, 19 Aug 2026 14:19:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4CF9910E576; Wed, 19 Aug 2026 14:19:05 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="fRdCBY61"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6DAA810E576 for ; Wed, 19 Aug 2026 14:19:04 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 7DF7E60A88; Wed, 19 Aug 2026 14:19:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EF7F1F00A3A; Wed, 19 Aug 2026 14:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787149143; bh=6rYV8u9cAq3VwmJG5tjX5EWOV1rf+rdFMkUNdfBKsdo=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=fRdCBY61U4D9pN2v9BBB/zDOxolyTjVP2DWVfWvsCBU2ecjdkwR7nQm23RrLF/Ebu a8eDBuZ1agZS+DgjY8CkQIJDwfipGAF99BCE9d1fyuOCR6lbUdlg2UkePSc+9Orj8L UtUCGrGioJis7FguH7lyG8EpTuD79MllTGRROuUkNGsjmO/hj4/XxI1Tk6J4pXSVMe Un4nX9MHkZdtqUrb554dmg0xE3kAE+C6r+WJQkq5b1hF9LOPPoYGjWtjsA0pZN7802 8C1tuO7MAwWlV2wd4dX21ssgt6zFG+bOmX62sDYr28wlnbczH8FoWw9XSZk/Ww+BKX VoRJptsRwU50g== Message-ID: <4ef74e14-8433-4619-ac97-62868c8799d1@kernel.org> Date: Wed, 19 Aug 2026 16:18:51 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 03/15] accel/qda: Add initial QDA DRM accelerator driver To: Ekansh Gupta , Oded Gabbay , Jonathan Corbet , Shuah Khan , Randy Dunlap , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , "Joerg Roedel (AMD)" , Will Deacon , Robin Murphy , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= Cc: Bharath Kumar , Chenna Kesava Raju , srinivas.kandagatla@oss.qualcomm.com, dmitry.baryshkov@oss.qualcomm.com, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org, llvm@lists.linux.dev, iommu@lists.linux.dev, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org References: <20260817-qda-v2-v2-0-69a02e9090d4@oss.qualcomm.com> <20260817-qda-v2-v2-3-69a02e9090d4@oss.qualcomm.com> <81708487-89ce-4cd5-b39a-2989bdce6088@kernel.org> <3476b5c3-7983-4994-a901-3d7d8bd75255@oss.qualcomm.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit 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" On 19/08/2026 15:17, Ekansh Gupta wrote: > On 19-08-2026 00:40, Krzysztof Kozlowski wrote: >> On 17/08/2026 06:47, Ekansh Gupta wrote: >>> Add the skeleton of the Qualcomm DSP Accelerator (QDA) driver, a DRM >>> accel driver for the Hexagon DSPs found on Qualcomm SoCs. >>> >>> This patch registers a DRM accel device, exposing a /dev/accel/accelN >>> character device node, and binds it to the RPMsg channel used to reach >>> the DSP. Buffer management, IOMMU context banks and the FastRPC >>> protocol are added by later patches in this series. >>> >>> qda_drv.c / qda_drv.h define the drm_driver ops table, the per-file >>> private state (qda_file_priv) and the main device structure (qda_dev), >>> which embeds drm_device so that it can be recovered with container_of(). >>> >>> qda_rpmsg.c binds to the "qcom,fastrpc" compatible via >>> module_rpmsg_driver(), reads the DSP domain name from the "label" >>> device-tree property, and registers the DRM device. >>> >>> Assisted-by: Claude:claude-sonnet-5 >>> Signed-off-by: Ekansh Gupta >>> --- >>> Changes in v2: >>> - Use module_rpmsg_driver() and drop the qda_rpmsg_register()/ >>> _unregister() wrappers, module_init()/module_exit() and >>> qda_rpmsg.h entirely (Dmitry Baryshkov) >>> - Read the "label" property directly into qdev->dsp_name (Dmitry Baryshkov) >>> - Drop the probe/remove/init log messages (Dmitry Baryshkov) >>> - Return the result of qda_register_device() directly (Dmitry Baryshkov) >>> - Clarify the Kconfig help text (Dmitry Baryshkov) >>> --- >>> drivers/accel/Kconfig | 1 + >>> drivers/accel/Makefile | 1 + >>> drivers/accel/qda/Kconfig | 30 ++++++++++++++++ >>> drivers/accel/qda/Makefile | 10 ++++++ >>> drivers/accel/qda/qda_drv.c | 71 ++++++++++++++++++++++++++++++++++++++ >>> drivers/accel/qda/qda_drv.h | 61 +++++++++++++++++++++++++++++++++ >>> drivers/accel/qda/qda_rpmsg.c | 79 +++++++++++++++++++++++++++++++++++++++++++ >>> 7 files changed, 253 insertions(+) >>> >>> diff --git a/drivers/accel/Kconfig b/drivers/accel/Kconfig >>> index bdf48ccafcf2..74ac0f71bc9d 100644 >>> --- a/drivers/accel/Kconfig >>> +++ b/drivers/accel/Kconfig >>> @@ -29,6 +29,7 @@ source "drivers/accel/ethosu/Kconfig" >>> source "drivers/accel/habanalabs/Kconfig" >>> source "drivers/accel/ivpu/Kconfig" >>> source "drivers/accel/qaic/Kconfig" >>> +source "drivers/accel/qda/Kconfig" >>> source "drivers/accel/rocket/Kconfig" >>> >>> endif >>> diff --git a/drivers/accel/Makefile b/drivers/accel/Makefile >>> index 1d3a7251b950..58c08dd5f389 100644 >>> --- a/drivers/accel/Makefile >>> +++ b/drivers/accel/Makefile >>> @@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_ACCEL_ARM_ETHOSU) += ethosu/ >>> obj-$(CONFIG_DRM_ACCEL_HABANALABS) += habanalabs/ >>> obj-$(CONFIG_DRM_ACCEL_IVPU) += ivpu/ >>> obj-$(CONFIG_DRM_ACCEL_QAIC) += qaic/ >>> +obj-$(CONFIG_DRM_ACCEL_QDA) += qda/ >>> obj-$(CONFIG_DRM_ACCEL_ROCKET) += rocket/ >>> \ No newline at end of file >> >> You have trivial patch errors. > newline problem was already there, wasn't introduced as part of this > patch series, so I wasn't sure to fix it here. I can fix this in v3.> >> ... >> >>> +} >>> + >>> +static const struct of_device_id qda_rpmsg_id_table[] = { >>> + { .compatible = "qcom,fastrpc" }, >>> + {}, >> >> Device node with this compatible is already populated, so this looks >> simply wrong or you are adding a duplicated driver. >> >> That's a no-go, you are supposed to work with existing drivers and grow >> them. > I'll bring the discussion again here, there was a discussion to move the > driver to accel subsystem if we want to support new features/uAPI > changes. Please read [1],[2] threads. The intention is to replace > fastrpc driver with QDA eventually. None of them address the problem. You want to grow fastrpc into user of dmabuf? So you move it from misc to here. Again: you have one driver. > > Do you suggest adding a different compatible, say "qcom,qda" for this > driver? How would that even work? How much (or many?) hardware do you have in your SoC? > > Let me know if you have a better suggestion to proceed here. > > [1] https://lkml.org/lkml/2024/6/24/479 > [2] https://lkml.org/lkml/2024/6/21/1252> Please do not ever reference lkml.org, it's long time deprecated and barely working. Use lore. Best regards, Krzysztof