Linux-Media Archive on lore.kernel.org
 help / color / Atom feed
From: Ezequiel Garcia <ezequiel@collabora.com>
To: linux-media@vger.kernel.org
Cc: Hans Verkuil <hverkuil@xs4all.nl>,
	Ezequiel Garcia <ezequiel@collabora.com>,
	kernel@collabora.com
Subject: [PATCH v2] v4l2-core: Print control name in VIDIOC_S/G_(EXT)_CTRL(S)
Date: Wed,  1 Jul 2020 10:17:30 -0300
Message-ID: <20200701131730.122209-1-ezequiel@collabora.com> (raw)
In-Reply-To: <20200609121514.9414-1-ezequiel@collabora.com>

While debugging, it's currently really hard to identify controls
by their ID. Print the control name making the print more helpful.

With this change, the print changes from:

video1: VIDIOC_S_EXT_CTRLS: which=0xf010000, count=5, error_idx=4, request_fd=45, id/size=0x990ce8/1048, id/size=0x990ce9/12, id/size=0x990cea/480, id/size=0x990ceb/896, id/size=0x990cec/400

to:

video1: VIDIOC_S_EXT_CTRLS: which=0xf010000, count=5, error_idx=4, request_fd=42, name=H264 Sequence Parameter Set, id/size=0x990ce8/1048, name=H264 Picture Parameter Set, id/size=0x990ce9/12, name=H264 Scaling Matrix, id/size=0x990cea/480, name=H264 Slice Parameters, id/size=0x990ceb/896, name=H264 Decode Parameters, id/size=0x990cec/400

For instance, this is specially helpful when the ioctl fails. Consider
the following example:

v4l2-ctrls: prepare_ext_ctrls: video1: pointer control id 0x990cec size too small, 400 bytes but 784 bytes needed
v4l2-ctrls: try_set_ext_ctrls: video1: video1: try_set_ext_ctrls_common failed (-14)
video1: VIDIOC_S_EXT_CTRLS: error -14: which=0xf010000, count=5, error_idx=5, request_fd=39, name=H264 Sequence Parameter Set, id/size=0x990ce8/1048, name=H264 Picture Parameter Set, id/size=0x990ce9/12, name=H264 Scaling Matrix, id/size=0x990cea/480, name=H264 Slice Parameters, id/size=0x990ceb/896, name=H264 Decode Parameters, id/size=0x990cec/400

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
v2:
* As requested by Hans, only print the name if non-null.
---
 drivers/media/v4l2-core/v4l2-ioctl.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 02bfef0da76d..a556880f225a 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -582,7 +582,10 @@ static void v4l_print_querymenu(const void *arg, bool write_only)
 static void v4l_print_control(const void *arg, bool write_only)
 {
 	const struct v4l2_control *p = arg;
+	const char *name = v4l2_ctrl_get_name(p->id);
 
+	if (name)
+		pr_cont("name=%s, ", name);
 	pr_cont("id=0x%x, value=%d\n", p->id, p->value);
 }
 
@@ -594,12 +597,15 @@ static void v4l_print_ext_controls(const void *arg, bool write_only)
 	pr_cont("which=0x%x, count=%d, error_idx=%d, request_fd=%d",
 			p->which, p->count, p->error_idx, p->request_fd);
 	for (i = 0; i < p->count; i++) {
+		unsigned int id = p->controls[i].id;
+		const char *name = v4l2_ctrl_get_name(id);
+
+		if (name)
+			pr_cont(", name=%s", name);
 		if (!p->controls[i].size)
-			pr_cont(", id/val=0x%x/0x%x",
-				p->controls[i].id, p->controls[i].value);
+			pr_cont(", id/val=0x%x/0x%x", id, p->controls[i].value);
 		else
-			pr_cont(", id/size=0x%x/%u",
-				p->controls[i].id, p->controls[i].size);
+			pr_cont(", id/size=0x%x/%u", id, p->controls[i].size);
 	}
 	pr_cont("\n");
 }
-- 
2.26.0.rc2


      parent reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-09 12:15 [PATCH] " Ezequiel Garcia
2020-06-11 12:35 ` Helen Koike
2020-06-11 14:29   ` Helen Koike
2020-06-23 11:01 ` Hans Verkuil
2020-06-23 12:32   ` Ezequiel Garcia
2020-07-01 13:17 ` Ezequiel Garcia [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200701131730.122209-1-ezequiel@collabora.com \
    --to=ezequiel@collabora.com \
    --cc=hverkuil@xs4all.nl \
    --cc=kernel@collabora.com \
    --cc=linux-media@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Media Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-media/0 linux-media/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-media linux-media/ https://lore.kernel.org/linux-media \
		linux-media@vger.kernel.org
	public-inbox-index linux-media

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-media


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git