From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpbgsg1.qq.com (smtpbgsg1.qq.com [54.254.200.92]) (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 13F311482E8 for ; Wed, 29 Apr 2026 01:16:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.254.200.92 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777425382; cv=none; b=d/3v70kdO76lEqCJiZEsSW8PM8XQFcMuCIxxofhYrqy4KKG0XbyjWOIQ3Eyb8iQKVIegVAP96sF+uMemhVRF6x1a4B3QZ84c0VOnsu7d0wuFf3MbOvnmxVLT3R8mJzl/Tw8BRAlPE13o1p0k38X98377dgKg8mmXe+siysabxu8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777425382; c=relaxed/simple; bh=S+FNbfKs3zWzpba+7WwK68JDLp3UZ3kapy9H/lK6Gi4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bepAyDqldUgaU7AUkhQjH8pOs+ImVyE9Yg3igtIaqkAEiynlWUFajIZqi9G7AqMhvy3ZL+Nj+bqAMSn1FsHw5AJL5eoW7831aKr05KaolUSi0SeMaQh5ICoPvM8MNAJK53mfA+ly6Yh7V2/9tOnbx/oylPa0V1r73WN/7m1mpxM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uniontech.com; spf=pass smtp.mailfrom=uniontech.com; dkim=pass (1024-bit key) header.d=uniontech.com header.i=@uniontech.com header.b=Zmk/UYoz; arc=none smtp.client-ip=54.254.200.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uniontech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=uniontech.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=uniontech.com header.i=@uniontech.com header.b="Zmk/UYoz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uniontech.com; s=onoh2408; t=1777425378; bh=S+FNbfKs3zWzpba+7WwK68JDLp3UZ3kapy9H/lK6Gi4=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=Zmk/UYozO08t3ZIZGbxo0FBEr9SumSHwa3msNi966lVTPM8u7GX9hA0A0ClgetQsv 9qd25c90JCacxxVmC7eeC0s+zVPqdoHwc8unOdZmJ76ozAiq2W+I1LoDLvxuIMLFR+ QcTgKC1UCE085ESexo6tPey8sSPufzU4yB9i3BYo= X-QQ-mid: zesmtpip3t1777425373td3ec577c X-QQ-Originating-IP: GDJcawdk+BQ6NHO957GYWgpbBB1B8/YjOfUyxDCvAHA= Received: from localhost.localdomain ( [localhost]) by bizesmtp.qq.com (ESMTP) with id ; Wed, 29 Apr 2026 09:16:11 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 1 X-BIZMAIL-ID: 3897802648851776766 EX-QQ-RecipientCnt: 12 From: Haowen Tu To: laurent.pinchart@ideasonboard.com Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, hansg@kernel.org, mchehab@kernel.org, rafael@kernel.org, lenb@kernel.org, pavel@kernel.org, linux-pm@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Haowen Tu Subject: Re: [PATCH 2/2] media: uvcvideo: skip resume when writing hibernation image Date: Wed, 29 Apr 2026 09:16:11 +0800 Message-Id: <20260429011611.1936498-1-tuhaowen@uniontech.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20260428091356.GF3219146@killaraus.ideasonboard.com> References: <20260428091356.GF3219146@killaraus.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-QQ-SENDSIZE: 520 Feedback-ID: zesmtpip:uniontech.com:qybglogicsvrsz:qybglogicsvrsz3b-0 X-QQ-XMAILINFO: NlVgJxuVJf8StkM1J2ZmG2chZvjRSewUESoZQ46I8zeGzBlp3WQnU/mj uEX4lUUVTXs6dslUHrhQspBnZY1mcnHQBTkC1pjneBLpxu5A5DzJhoKkXh1toujY2fRu574 7rx6CqvNdDya39WOpHix9QztHCZU+KYwpKgRjdxHWN0fWho2rfzD1NjGbZ7gPXGRYV45EYt E2vDJWNlzZUka/KCvvUuqxX5dZJ3afwGFKOjvcIVkaJMsx3LT/tfKBw9/PAwlT9WVB9Ve4Y 6BVc0pXUWggevr3yTKvo9fW9H9H2LX7d6N2DdGlrPrbCM3OMOQ9twVwX3AXqgBJ8FJjkeA0 su7ASgVRTgDZUJVcCFDx80ZBRQ0+fUoAZkLNmLhju9tYOhgwhoPAlz2gqg5HL+nhWOE3FT4 iYFmWjrpu1GcTuM8tHuRLdQo1EsNaocYLMeV4aBDuZ7KH6CTz051BbxDvec3Bie1035k/oW lclG0QbF8W0B89EHgky9SLFg4mQM3IOYQQuyWzfjB1wC6u2FcE8T+xdDMa76HUgfK/Ie0kx wuLOZc/ahKVb/6Iqo8t89UwC6535Vlud1jm3uwutTgO02J5gjXovzer1TDz7/0obyPNxIA+ YbJkOOI6pXsZRCI7UZlkC6/FehAToTAF57/AIocTk+SIJDh5yl1VvhYNn3KNGzG1WfocAHZ OXq32e0OYnLiALjbxdkGgDPqXVWOpLHNe7F9VdGfHdiyh3V80eFT4BP90Hr+dFzVVzfBDA/ BwR1K5jfoKV+n0jt6weWIeKZrfco2SKaddLgi89K8feXUEN2jJeK+yyw49Q1VJGpmubzwQa oMBt45mu8aZq5yz7Kj2zW8WPX2fO3BYN3FQ/S+T+jeCZGIXaVnidb9JQtSAJi9A1lBFi/vy nj7zSOzpIwDSvEF5+VTKOtqRoA7rvV9u+HZn856wJ2yXd0fv0iLsfdFue3NZFHRiHi0q9V0 ZuTHqKh+Ke+1CLTh0TZrzgEjwK4eo+jXGcsguYcMXEERat+7Jqr8HfTqfMGFdFp1Bqx8ZTU 2K53RUz82DjVJKy/+LxEsEdC5bnhPceqBUtv1Mu3qxdkBmpYuLV3MTSWAPtbULyzJe1zrrX mZcRvbPE/21dAjArcxO0IjCmn7IVhFewU9WmHOzHvu+ X-QQ-XMRINFO: OD9hHCdaPRBwH5bRRRw8tsiH4UAatJqXfg== X-QQ-RECHKSPAM: 0 Hi Laurent, On Tue, Apr 28, 2026 at 12:13:56PM +0300, Laurent Pinchart wrote: > Will all leaf drivers need to implement something similar ? How does > that scale ? Thanks, that's a very valid concern. If this pattern ends up being needed in multiple USB interface drivers, then handling it in each leaf driver would clearly not scale well. My initial motivation was that the UVC streaming resume path is reached from usb_driver.resume(), which doesn't expose the hibernation PM message. As a result, the driver has no way to distinguish PMSG_THAW from PMSG_RESTORE locally. That said, I agree this points to a USB-level design question rather than just a UVC-specific one. I'll revisit the approach with that in mind, and will include the USB maintainers and list in the next round. Thanks, Haowen