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 1B0F3282F1F for ; Tue, 5 May 2026 06:33:51 +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=1777962831; cv=none; b=JKlhh5HLCxo7b7NRpO4f3cezbKYa6WrypK4rjZRCKXTCSadaj8euLfwQ7mOQTWd7avcNltSLY529DCTiGR55li39A6OY1SUOf0/q4C5lChHSL+2PorF1SUZBGCBDwIWi8f9DfPLL/5/jLr+GtkIks2T6FI4fpDOdcz6BwaxKWQo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777962831; c=relaxed/simple; bh=QPV+RLpgGZs7TEEIW8+YoXp/qWEO+LNijZEAnqFVbBc=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=eMmqvFpnA5u5iWWGVphGoLoxM1PUvnKAdF+7227b04f8GctbqrqNzvewHhcTS9s+YVnLc03m2hzTQ8FoYi04iv7BR2gFTJ6YLo9MYdfBx0q9jkv4/+9mOyxdwvqr/OS9UVHFXOtuHs3r7j5Mkirn4ts4Kq0liAAOta9CFjdYYho= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JLPOPueQ; 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="JLPOPueQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08D95C2BCB4; Tue, 5 May 2026 06:33:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777962830; bh=QPV+RLpgGZs7TEEIW8+YoXp/qWEO+LNijZEAnqFVbBc=; h=Date:From:Subject:To:Cc:References:In-Reply-To:From; b=JLPOPueQ4+86OSLfLkT/phB1T4R13otX/TIhH1MtBcj54oytiCC7liyMB7H37SLWg 93Re9a4jrREQpCWQ0GMDSeZPJE2Zw4BvIhbxuQxR/IpJR6XssaNObaHw8S3p1FTpSG Q0G+T7pdeb6To+fgSMgS84GQopK0q7aRn4F0ySsJBmwZ43pImhyw/E//rSOy8bKAUj EXFI4vm4twuF9znRHnasvknYhrv2UdQ1SRA4jfY/YyWWyzjlpNnQRRw93X8vrs5ypt gHV6qJGTYE4P3nAv34w7I53luESsn/hbDXUfWu1Io0g0nz78O+SJTnbDnqfTQf2zdA PNVuJ0kelGOsA== Message-ID: Date: Tue, 5 May 2026 08:33:43 +0200 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Hans Verkuil Subject: Re: [PATCH v4 20/29] media: uapi: Bump the STREAMS bit a little To: Sakari Ailus , linux-media@vger.kernel.org Cc: laurent.pinchart@ideasonboard.com, Prabhakar , Kate Hsuan , Dave Stevenson , Tommaso Merciai , Benjamin Mugnier , Sylvain Petinot , Christophe JAILLET , Julien Massot , Naushir Patuck , "Yan, Dongcheng" , "Cao, Bingbu" , "Qiu, Tian Shu" , Stefan Klug , Mirela Rabulea , =?UTF-8?Q?Andr=C3=A9_Apitzsch?= , Heimir Thor Sverrisson , Kieran Bingham , Mehdi Djait , Ricardo Ribalda Delgado , Hans de Goede , Jacopo Mondi , Tomi Valkeinen , David Plowman , "Yu, Ong Hock" , "Ng, Khai Wen" , Jai Luthra , Rishikesh Donadkar References: <20260408153939.969381-1-sakari.ailus@linux.intel.com> <20260408153939.969381-21-sakari.ailus@linux.intel.com> Content-Language: en-US, nl In-Reply-To: <20260408153939.969381-21-sakari.ailus@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 08/04/2026 17:39, Sakari Ailus wrote: > Bump the V4L2_SUBDEV_CAP_STREAMS by one bit up, order to avoid confusing > libcamera with streams that has moved forward from the original libcamera > implementation. The bit can presumably be taken into use but only after > the other free bits. The commit log must explain why this is safe to do. In this case because v4l2_subdev_enable_streams_api is currently always false, which means that this capability is always removed. It's also not clear to me why this is important for libcamera. Since the streams API is still disabled, any libcamera code depending on it should be purely for testing, right? Regardless, this uAPI change needs to be documented a lot better. Regards, Hans > > Signed-off-by: Sakari Ailus > --- > include/uapi/linux/v4l2-subdev.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h > index 2347e266cf75..6160c3e21436 100644 > --- a/include/uapi/linux/v4l2-subdev.h > +++ b/include/uapi/linux/v4l2-subdev.h > @@ -196,8 +196,11 @@ struct v4l2_subdev_capability { > /* The v4l2 sub-device video device node is registered in read-only mode. */ > #define V4L2_SUBDEV_CAP_RO_SUBDEV 0x00000001 > > +/* Reserved, old STREAMS bit libcamera used before API stabilisation. */ > +/* #define V4L2_SUBDEV_CAP_STREAMS_PRELIMINARY 0x00000002 */ > + > /* The v4l2 sub-device supports routing and multiplexed streams. */ > -#define V4L2_SUBDEV_CAP_STREAMS 0x00000002 > +#define V4L2_SUBDEV_CAP_STREAMS 0x00000004 > > /* > * Is the route active? An active route will start when streaming is enabled