From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BAB5B245022; Mon, 27 Oct 2025 13:10:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761570623; cv=none; b=KzVC6l6mnIh/rXKGE7MFrXiaP9PkjF64cpuRPhymRIQC6MiKL5vgz9E4jWLVJ+YcZ7cmqLAfJJwgjDNpSVnBi6JZkH3yCzR30CW+OJyTM+SY3iDD3q8kpzGcRt+BtJuAKbBw/xtlGld7sAunAG0dYDSk9afVAzvE4k2FUWoLGp0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761570623; c=relaxed/simple; bh=oQmm+wvIDMShfnALqPD7wwl33FnC85XhswN//H+pbp8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TTpdYVKC0wgI1wpLG6d0UVYg26wyqW4FqJ7Iz6ihFbHjnLcKqdt6qfmImthwMgRyUz+cqnORZrK1al6GYc/kxgVq3V9ovIm1P5oj1JC7x4gYzuEc/shhXveDjg0A/jidi9GJ8Q4VP8vwFpFzKnB3t3jZMxkgIfj3RUcx0pEtg1g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X13+xhpl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="X13+xhpl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0529EC4CEFF; Mon, 27 Oct 2025 13:10:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761570623; bh=oQmm+wvIDMShfnALqPD7wwl33FnC85XhswN//H+pbp8=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=X13+xhplCXsjWqBnlnhDbz7hYz8xE65UGoHPkd9Cw9FeJrxoQXWliigGkMgKlyWCr QgJ9yT27/M0MyZXxKsNQXu5kPaNUsRsR8VSj9aDK6MojBBdsMTIM11CYPOfyc2276z QDCE++RfBO3YmJdfGE/piBTkPEzRAFin62hLHwQbcOG1MK5tTdeSCrtnZ5ibGTKyNp jQOxNWQ6LVdOek8fAm2IGmIRx7JUhAbEfxrx+HNzev6IXdnVuMA575STmCVwBfTWAS x/wgIITxB7SYCSQurqKtSyLhTNevnl06tr1rhq0WwpzQN287sP/HyrXnfCq85zoFBH WB3rqqH16ZB2g== Message-ID: Date: Mon, 27 Oct 2025 14:10:18 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] decoder: Add V4L2 stateless H.264 decoder driver To: zhentao.guo@amlogic.com, Mauro Carvalho Chehab , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org References: <20251027-b4-s4-vdec-upstream-v1-0-620401813b5d@amlogic.com> <20251027-b4-s4-vdec-upstream-v1-3-620401813b5d@amlogic.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 27/10/2025 06:42, Zhentao Guo via B4 Relay wrote: > From: Zhentao Guo > > This patch introduces initial driver support for Amlogic's new Please do not use "This commit/patch/change", but imperative mood. See longer explanation here: https://elixir.bootlin.com/linux/v6.16/source/Documentation/process/submitting-patches.rst#L94 > video acceleration hardware architecture, designed for video > stream decoding. The driver is designed to support the > V4L2 M2M stateless decoder API. In phase 1, it supports H.264 > bitstreams decoding. > > Signed-off-by: Zhentao Guo ... > + > +static int aml_vdec_drv_probe(struct platform_device *pdev) > +{ > + struct aml_vdec_dev *dev; > + struct video_device *vfd_dec; > + struct aml_vdec_hw *hw; > + int ret = 0; > + > + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return -ENOMEM; > + > + dev->plat_dev = pdev; > + mutex_init(&dev->dev_mutex); > + > + ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "v4l2_device_register err\n"); > + > + vfd_dec = video_device_alloc(); > + if (!vfd_dec) { > + v4l2_err(&dev->v4l2_dev, "Failed to allocate video device\n"); > + ret = -ENOMEM; > + goto err_device_alloc; > + } > + *vfd_dec = dec_dev; > + vfd_dec->v4l2_dev = &dev->v4l2_dev; > + vfd_dec->lock = &dev->dev_mutex; > + video_set_drvdata(vfd_dec, dev); > + dev->vfd = vfd_dec; > + platform_set_drvdata(pdev, dev); > + > + hw = kzalloc(sizeof(*hw), GFP_KERNEL); Why aren't you using devm interfaces? > + if (!hw) { > + ret = -ENOMEM; > + goto err_dec_mem_init; > + } > + dev->dec_hw = hw; > + > + dev->pvdec_data = of_device_get_match_data(&pdev->dev); > + ret = dev->pvdec_data->req_hw_resource(dev); > + if (ret < 0) > + goto err_hw_init; > + > + dev->m2m_dev_dec = v4l2_m2m_init(&aml_vdec_m2m_ops); > + if (IS_ERR((__force void *)dev->m2m_dev_dec)) { Huh? Why the cast? > + v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem dec device\n"); > + ret = PTR_ERR((__force void *)dev->m2m_dev_dec); > + goto err_hw_init; > + } > + > + ret = video_register_device(vfd_dec, VFL_TYPE_VIDEO, -1); > + if (ret) { > + v4l2_err(&dev->v4l2_dev, "Failed to register video device"); > + goto err_vid_dev_register; > + } > + > + v4l2_info(&dev->v4l2_dev, "Registered %s as /dev/%s\n", > + vfd_dec->name, video_device_node_name(vfd_dec)); This does not look like useful printk message. Drivers should be silent on success: https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/coding-style.rst#L913 https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/debugging/driver_development_debugging_guide.rst#L79 > + > + dev->mdev.dev = &pdev->dev; > + strscpy(dev->mdev.model, AML_VDEC_DRV_NAME, sizeof(dev->mdev.model)); > + media_device_init(&dev->mdev); > + dev->mdev.ops = &aml_m2m_media_ops; > + dev->v4l2_dev.mdev = &dev->mdev; > + > + ret = v4l2_m2m_register_media_controller(dev->m2m_dev_dec, vfd_dec, > + MEDIA_ENT_F_PROC_VIDEO_DECODER); > + if (ret) { > + v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem media controller\n"); > + goto error_m2m_mc_register; > + } > + > + ret = media_device_register(&dev->mdev); > + if (ret) { > + v4l2_err(&dev->v4l2_dev, "Failed to register media device"); > + goto err_media_dev_register; > + } > + vdec_enable(dev->dec_hw); > + return 0; > + > +err_media_dev_register: > + v4l2_m2m_unregister_media_controller(dev->m2m_dev_dec); > +error_m2m_mc_register: > + media_device_cleanup(&dev->mdev); > +err_vid_dev_register: > + v4l2_m2m_release(dev->m2m_dev_dec); > +err_hw_init: > + kfree(hw); > + dev->dec_hw = NULL; > +err_dec_mem_init: > + video_device_release(vfd_dec); > +err_device_alloc: > + v4l2_device_unregister(&dev->v4l2_dev); > + return ret; > +} > + > +static void aml_vdec_drv_remove(struct platform_device *pdev) > +{ > + struct aml_vdec_dev *dev = platform_get_drvdata(pdev); > + > + vdec_disable(dev->dec_hw); > + > + if (media_devnode_is_registered(dev->mdev.devnode)) { > + media_device_unregister(&dev->mdev); > + media_device_cleanup(&dev->mdev); > + } > + > + if (dev->m2m_dev_dec) > + v4l2_m2m_release(dev->m2m_dev_dec); > + if (dev->vfd) > + video_unregister_device(dev->vfd); > + if (dev->dec_hw) > + dev->pvdec_data->destroy_hw_resource(dev); > + > + v4l2_device_unregister(&dev->v4l2_dev); > + > + pr_debug("aml v4l2 decoder driver remove\n"); This does not look like useful printk message. Drivers should be silent on success: https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/coding-style.rst#L913 https://elixir.bootlin.com/linux/v6.15-rc7/source/Documentation/process/debugging/driver_development_debugging_guide.rst#L79 > +} > + > +static const struct of_device_id aml_vdec_match[] = { > + {.compatible = "amlogic,s4-vcodec-dec", .data = &aml_vdec_s4_pdata}, > + {}, > +}; > + > +static struct platform_driver aml_vcodec_dec_driver = { > + .probe = aml_vdec_drv_probe, > + .remove = aml_vdec_drv_remove, > + .driver = { > + .name = AML_VDEC_DRV_NAME, > + .of_match_table = aml_vdec_match, > + }, > +}; > + > +static int __init aml_vdec_init(void) > +{ > + pr_debug("aml v4l2 decoder module init\n"); > + > + if (platform_driver_register(&aml_vcodec_dec_driver)) { > + pr_err("failed to register aml v4l2 decoder\n"); > + return -ENODEV; > + } > + > + return 0; > +} > + > +static void __exit aml_vdec_exit(void) > +{ > + pr_debug("aml v4l2 decoder module exit\n"); > + platform_driver_unregister(&aml_vcodec_dec_driver); No, drop entire init/exit. This is some really odd code, probably copy-paste from poor downstream. Please look at upstream drivers - do you see anything like that anywhere? > +} > + > +module_init(aml_vdec_init); > +module_exit(aml_vdec_exit); > + Best regards, Krzysztof