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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9764C3815B for ; Wed, 15 Apr 2020 09:57:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9628A20775 for ; Wed, 15 Apr 2020 09:57:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b="vjbC/xpy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405833AbgDOJ5s (ORCPT ); Wed, 15 Apr 2020 05:57:48 -0400 Received: from lb1-smtp-cloud7.xs4all.net ([194.109.24.24]:60495 "EHLO lb1-smtp-cloud7.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405628AbgDOJ5p (ORCPT ); Wed, 15 Apr 2020 05:57:45 -0400 Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud7.xs4all.net with ESMTPA id OenYjVcGK7xncOencj4KPc; Wed, 15 Apr 2020 11:57:41 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s1; t=1586944661; bh=S1nm6MvMqHYJL+VZyu/2muqCMgV1+EDqPTh0gEMNd+k=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=vjbC/xpy5XjUMRobGRFNrlZaE3soXlEenJTwKOb+VPWb9GgZi22h5y8lqxBtPU2Ix DjfN1MIgdcwpSMguB1sitQyXOqJR+K878i2gGys11Ul3i6vJM6p2cCkfub9DGGxOaY HoZGW1alTJOFr8dWma9LP4t9KxsUwr8eo8M+NoNnWGY3+6F3Uc1xRZzobts9u8NoC6 PvulfK72XccNLhage0E0qg40Iilc4leenfBXUWwaOUw4w3LPLs9Wv/ykwM55b5wV0x nA0tK5o+mWcf4YO1Bc+4wVy2zTBnpxHgzLHbuF4mzUSkxGDo0QgfXvH3yPu2BJBB0G 7dpRH6otxDjhw== Subject: Re: [PATCH v7 1/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC To: Laurent Pinchart Cc: =?UTF-8?Q?Niklas_S=c3=b6derlund?= , Helen Koike , Sakari Ailus , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org References: <20200413202351.1359754-1-niklas.soderlund+renesas@ragnatech.se> <20200413202351.1359754-2-niklas.soderlund+renesas@ragnatech.se> <20200414233641.GU19819@pendragon.ideasonboard.com> From: Hans Verkuil Message-ID: Date: Wed, 15 Apr 2020 11:57:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200414233641.GU19819@pendragon.ideasonboard.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-CMAE-Envelope: MS4wfFDaYK7fC/TZgEMeGVU9GVaqMUKZQP0wg0pG5PRyPhSNFrZ4xhSBat+pXDqD2mgmm6OYEzD/4bR5lo3FP/fYviCM0jyvvNPmH5MfyH+7SKyZpyQYSCyj Y+nbBJp5iUd1yLlsIhG3RnVISlFu1w1uVs2596ZANTRr15h6HoY4f7XvHlGzFhM+CCSrPyZH2W9YaQGB9hKPn8utUl5AQlQyPi3s1HCkBBBGdmjBp1AxZ4gF KvAlI7llbwbIpJG0frbkR6NvAOQ+4z2X8dUJRfpz4F08cer6RySAouZDalQm8I78zoB8V2XyYCAcWOOFt1I247yqNR8JXmLr6a504F0HZ+TkU6PuglBDrgoy k4lL03ryuOIGtZ0ieapcTWxkKRTNHqOb0oDnoT0N4G6ig/wDNfgJ0AaXxVQLJP9GI+VBxjaV Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 15/04/2020 01:36, Laurent Pinchart wrote: > Hi Hans, > > On Tue, Apr 14, 2020 at 01:42:46PM +0200, Hans Verkuil wrote: >> On 13/04/2020 22:23, Niklas Söderlund wrote: >>> Add a video device capability flag to indicate that its inputs and/or >>> outputs are controlled by the Media Controller instead of the V4L2 API. >>> When this flag is set, ioctl for enum inputs and outputs are >>> automatically enabled and programmed to call a helper function. >>> >>> Suggested-by: Hans Verkuil >>> Signed-off-by: Helen Koike >>> Signed-off-by: Niklas Söderlund >>> Acked-by: Sakari Ailus >>> Reviewed-by: Laurent Pinchart >>> --- >>> .../media/uapi/v4l/vidioc-querycap.rst | 6 ++ >>> .../media/videodev2.h.rst.exceptions | 1 + >>> drivers/media/v4l2-core/v4l2-dev.c | 25 ++++++-- >>> drivers/media/v4l2-core/v4l2-ioctl.c | 57 +++++++++++++++++-- >>> include/uapi/linux/videodev2.h | 2 + >>> 5 files changed, 81 insertions(+), 10 deletions(-) >>> >>> diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst >>> index 5f9930195d624c73..497a6aa2cbebad71 100644 >>> --- a/Documentation/media/uapi/v4l/vidioc-querycap.rst >>> +++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst >>> @@ -264,6 +264,12 @@ specification the ioctl returns an ``EINVAL`` error code. >>> * - ``V4L2_CAP_TOUCH`` >>> - 0x10000000 >>> - This is a touch device. >>> + * - ``V4L2_CAP_IO_MC`` >>> + - 0x20000000 >>> + - There is only one input and/or output seen from userspace. The whole >>> + video topology configuration, including which I/O entity is routed to >>> + the input/output, is configured by userspace via the Media Controller. >>> + See :ref:`media_controller`. >>> * - ``V4L2_CAP_DEVICE_CAPS`` >>> - 0x80000000 >>> - The driver fills the ``device_caps`` field. This capability can >>> diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions >>> index cb6ccf91776e6b56..a625fb90e3a989a7 100644 >>> --- a/Documentation/media/videodev2.h.rst.exceptions >>> +++ b/Documentation/media/videodev2.h.rst.exceptions >>> @@ -176,6 +176,7 @@ replace define V4L2_CAP_STREAMING device-capabilities >>> replace define V4L2_CAP_META_OUTPUT device-capabilities >>> replace define V4L2_CAP_DEVICE_CAPS device-capabilities >>> replace define V4L2_CAP_TOUCH device-capabilities >>> +replace define V4L2_CAP_IO_MC device-capabilities >>> >>> # V4L2 pix flags >>> replace define V4L2_PIX_FMT_PRIV_MAGIC :c:type:`v4l2_pix_format` >>> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c >>> index 97b6a3af13614639..3048811450182185 100644 >>> --- a/drivers/media/v4l2-core/v4l2-dev.c >>> +++ b/drivers/media/v4l2-core/v4l2-dev.c >>> @@ -552,6 +552,7 @@ static void determine_valid_ioctls(struct video_device *vdev) >>> (vdev->device_caps & meta_caps); >>> bool is_rx = vdev->vfl_dir != VFL_DIR_TX; >>> bool is_tx = vdev->vfl_dir != VFL_DIR_RX; >>> + bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC; >>> >>> bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE); >>> >>> @@ -725,9 +726,15 @@ static void determine_valid_ioctls(struct video_device *vdev) >>> SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std); >>> if (is_rx) { >>> SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd); >>> - SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input); >>> - SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input); >>> - SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input); >>> + if (is_io_mc && !is_meta) { >> >> I noticed the addition of !is_meta. Digging into the history I saw that it was >> a request from Sakari in the v4 review. I must have missed that since I disagree >> with that change. >> >> If IO_MC is set, then this applies to video/meta/vbi. After all, vbi is just a >> special kind of metadata (and we'd use a metadata device node if we would design >> that today), so it makes no sense to do something different for metadata. >> >> Another issue here is that video devices can be for video, for metadata, or for >> both. So if is_io_mc is true, then you would get different behavior depending >> on the type of video device: if it is just video, then it supports the INPUT >> ioctls, if it supports metadata as well, then it doesn't. > > As expressed before, I think we really should drop VIDIOC_ENUMINPUT, > VIDIOC_G_INPUT and VIDIOC_S_INPUT for devices that have V4L2_CAP_IO_MC > set. They can't be supported by generic video node-centric applications > that expect those ioctls to be supported in any case, so it makes little > sense. With V4L2_CAP_IO_MC added, the v4l2-compliance tool can ignore > those ioctls (or, even better, report an error if they're implemented). I know your opinion on this, and I disagree. All non-MC video capture or output devices support the input/output ioctls, and to suddenly make an exception is not a good idea IMHO. On the other hand, I do agree that it makes no sense that MC drivers would have to implement dummy ioctls. So having the core do this is, I think, a good compromise. In general I believe we should avoid introducing exceptions in the public API unless there is no alternative. In this case there is a workable alternative (dummy ioctls provided by the core). Regards, Hans > >> I would just keep this as it was originally: >> >> if (is_io_mc) { >> >>> + set_bit(_IOC_NR(VIDIOC_ENUMINPUT), valid_ioctls); >>> + set_bit(_IOC_NR(VIDIOC_G_INPUT), valid_ioctls); >>> + set_bit(_IOC_NR(VIDIOC_S_INPUT), valid_ioctls); >>> + } else { >>> + SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input); >>> + SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input); >>> + SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input); >>> + } >>> SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio); >>> SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio); >>> SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio); >>> @@ -735,9 +742,15 @@ static void determine_valid_ioctls(struct video_device *vdev) >>> SET_VALID_IOCTL(ops, VIDIOC_S_EDID, vidioc_s_edid); >>> } >>> if (is_tx) { >>> - SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output); >>> - SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output); >>> - SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output); >>> + if (is_io_mc && !is_meta) { >> >> Same here. >> >> The remainder of the series looks good (except that an additional cx18 patch is >> needed as Andrey pointed out on irc). >> >>> + set_bit(_IOC_NR(VIDIOC_ENUMOUTPUT), valid_ioctls); >>> + set_bit(_IOC_NR(VIDIOC_G_OUTPUT), valid_ioctls); >>> + set_bit(_IOC_NR(VIDIOC_S_OUTPUT), valid_ioctls); >>> + } else { >>> + SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output); >>> + SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output); >>> + SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output); >>> + } >>> SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout); >>> SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout); >>> SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout); >>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c >>> index b2ef8e60ea7da19d..afd1f427df557f71 100644 >>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c >>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c >>> @@ -1085,6 +1085,32 @@ static int v4l_querycap(const struct v4l2_ioctl_ops *ops, >>> return ret; >>> } >>> >>> +static int v4l_g_input(const struct v4l2_ioctl_ops *ops, >>> + struct file *file, void *fh, void *arg) >>> +{ >>> + struct video_device *vfd = video_devdata(file); >>> + >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) { >>> + *(int *)arg = 0; >>> + return 0; >>> + } >>> + >>> + return ops->vidioc_g_input(file, fh, arg); >>> +} >>> + >>> +static int v4l_g_output(const struct v4l2_ioctl_ops *ops, >>> + struct file *file, void *fh, void *arg) >>> +{ >>> + struct video_device *vfd = video_devdata(file); >>> + >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) { >>> + *(int *)arg = 0; >>> + return 0; >>> + } >>> + >>> + return ops->vidioc_g_output(file, fh, arg); >>> +} >>> + >>> static int v4l_s_input(const struct v4l2_ioctl_ops *ops, >>> struct file *file, void *fh, void *arg) >>> { >>> @@ -1094,12 +1120,21 @@ static int v4l_s_input(const struct v4l2_ioctl_ops *ops, >>> ret = v4l_enable_media_source(vfd); >>> if (ret) >>> return ret; >>> + >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) >>> + return *(int *)arg ? -EINVAL : 0; >>> + >>> return ops->vidioc_s_input(file, fh, *(unsigned int *)arg); >>> } >>> >>> static int v4l_s_output(const struct v4l2_ioctl_ops *ops, >>> struct file *file, void *fh, void *arg) >>> { >>> + struct video_device *vfd = video_devdata(file); >>> + >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) >>> + return *(int *)arg ? -EINVAL : 0; >>> + >>> return ops->vidioc_s_output(file, fh, *(unsigned int *)arg); >>> } >>> >>> @@ -1143,6 +1178,14 @@ static int v4l_enuminput(const struct v4l2_ioctl_ops *ops, >>> if (is_valid_ioctl(vfd, VIDIOC_S_STD)) >>> p->capabilities |= V4L2_IN_CAP_STD; >>> >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) { >>> + if (p->index) >>> + return -EINVAL; >>> + strscpy(p->name, vfd->name, sizeof(p->name)); >>> + p->type = V4L2_INPUT_TYPE_CAMERA; >>> + return 0; >>> + } >>> + >>> return ops->vidioc_enum_input(file, fh, p); >>> } >>> >>> @@ -1161,6 +1204,14 @@ static int v4l_enumoutput(const struct v4l2_ioctl_ops *ops, >>> if (is_valid_ioctl(vfd, VIDIOC_S_STD)) >>> p->capabilities |= V4L2_OUT_CAP_STD; >>> >>> + if (vfd->device_caps & V4L2_CAP_IO_MC) { >>> + if (p->index) >>> + return -EINVAL; >>> + strscpy(p->name, vfd->name, sizeof(p->name)); >>> + p->type = V4L2_OUTPUT_TYPE_ANALOG; >>> + return 0; >>> + } >>> + >>> return ops->vidioc_enum_output(file, fh, p); >>> } >>> >>> @@ -2683,10 +2734,8 @@ DEFINE_V4L_STUB_FUNC(expbuf) >>> DEFINE_V4L_STUB_FUNC(g_std) >>> DEFINE_V4L_STUB_FUNC(g_audio) >>> DEFINE_V4L_STUB_FUNC(s_audio) >>> -DEFINE_V4L_STUB_FUNC(g_input) >>> DEFINE_V4L_STUB_FUNC(g_edid) >>> DEFINE_V4L_STUB_FUNC(s_edid) >>> -DEFINE_V4L_STUB_FUNC(g_output) >>> DEFINE_V4L_STUB_FUNC(g_audout) >>> DEFINE_V4L_STUB_FUNC(s_audout) >>> DEFINE_V4L_STUB_FUNC(g_jpegcomp) >>> @@ -2735,11 +2784,11 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = { >>> IOCTL_INFO(VIDIOC_S_AUDIO, v4l_stub_s_audio, v4l_print_audio, INFO_FL_PRIO), >>> IOCTL_INFO(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)), >>> IOCTL_INFO(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)), >>> - IOCTL_INFO(VIDIOC_G_INPUT, v4l_stub_g_input, v4l_print_u32, 0), >>> + IOCTL_INFO(VIDIOC_G_INPUT, v4l_g_input, v4l_print_u32, 0), >>> IOCTL_INFO(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO), >>> IOCTL_INFO(VIDIOC_G_EDID, v4l_stub_g_edid, v4l_print_edid, INFO_FL_ALWAYS_COPY), >>> IOCTL_INFO(VIDIOC_S_EDID, v4l_stub_s_edid, v4l_print_edid, INFO_FL_PRIO | INFO_FL_ALWAYS_COPY), >>> - IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_stub_g_output, v4l_print_u32, 0), >>> + IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_g_output, v4l_print_u32, 0), >>> IOCTL_INFO(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO), >>> IOCTL_INFO(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)), >>> IOCTL_INFO(VIDIOC_G_AUDOUT, v4l_stub_g_audout, v4l_print_audioout, 0), >>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h >>> index 9817b7e2c968fd04..b18f3f7cde31c2e4 100644 >>> --- a/include/uapi/linux/videodev2.h >>> +++ b/include/uapi/linux/videodev2.h >>> @@ -487,6 +487,8 @@ struct v4l2_capability { >>> >>> #define V4L2_CAP_TOUCH 0x10000000 /* Is a touch device */ >>> >>> +#define V4L2_CAP_IO_MC 0x20000000 /* Is input/output controlled by the media controller */ >>> + >>> #define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */ >>> >>> /* >