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 823BC28E6 for ; Fri, 27 Oct 2023 07:19:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nOPH7MxC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7146FC433C7; Fri, 27 Oct 2023 07:19:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698391197; bh=eAzGncuNN+h/nEmL0ZN/dcXM9fGW6dn1TaiHf0175Cw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nOPH7MxC1fgBZD4Sr2OY9INWba7SOjh03byjzEY0Hg3jA6SPPpqqHDuT4zAnESK0o STR/y3RVFPBeVW+1Gu7xEUbXIGNhlWS/0jsqyKjR2j2QvR9z999NEiYDcuEdQFSlcv gURLO0OKq7yCHZDh3THAX4hJIsBmzZD3aqYa+BI0= Date: Fri, 27 Oct 2023 09:19:54 +0200 From: Greg KH To: Jayant Chowdhary Cc: mgr@pengutronix.de, Thinh.Nguyen@synopsys.com, arakesh@google.com, etalvala@google.com, dan.scally@ideasonboard.com, laurent.pinchart@ideasonboard.com, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, Michael Grzeschik Subject: Re: [PATCH v2] usb:gadget:uvc Do not use worker thread to pump usb requests Message-ID: <2023102739-reproach-salute-0d22@gregkh> References: <20231026215635.2478767-1-jchowdhary@google.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231026215635.2478767-1-jchowdhary@google.com> On Thu, Oct 26, 2023 at 09:56:35PM +0000, Jayant Chowdhary wrote: > This patch is based on top of > https://lore.kernel.org/linux-usb/20230930184821.310143-1-arakesh@google.com/T/#t: That doesn't work in the changelog of a patch at all, it goes below the --- line p lease. > > When we use an async work queue to perform the function of pumping > usb requests to the usb controller, it is possible that thread scheduling > affects at what cadence we're able to pump requests. This could mean usb > requests miss their uframes - resulting in video stream flickers on the host > device. > > In this patch, we move the pumping of usb requests to > 1) uvcg_video_complete() complete handler for both isoc + bulk > endpoints. We still send 0 length requests when there is no uvc buffer > available to encode. > 2) uvc_v4l2_qbuf - only for bulk endpoints since it is not legal to send > 0 length requests. > > Signed-off-by: Michael Grzeschik > Signed-off-by: Jayant Chowdhary > Suggested-by: Jayant Chowdhary > Suggested-by: Avichal Rakesh > Tested-by: Jayant Chowdhary > --- > v1->v2: Fix code style and add self Signed-off-by Great, but as signed-off-by kind of implies you tested it, no need for the tested-by now, right? Not a big deal, and normally I'd ignore it but I know you at least have to do one more version of this based on the above problem... thanks, greg k-h