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 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D259EC433EF for ; Thu, 19 May 2022 07:39:37 +0000 (UTC) Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.94.2) (envelope-from ) id 1nrakT-00048A-PI; Thu, 19 May 2022 03:39:05 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]) by shelob.surriel.com with esmtps (TLS1.2) tls TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nrakQ-00047X-LI for kernelnewbies@kernelnewbies.org; Thu, 19 May 2022 03:39:03 -0400 Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id E89615C0135; Thu, 19 May 2022 03:38:55 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Thu, 19 May 2022 03:38:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm1; t=1652945935; x=1653032335; bh=JlHqic7Lqs BADopy3n3gr2qpLmBLiebZIJyqFqagYKc=; b=Nne/nr85EsG5ilb3Eie76YHB+V 6ys6+b1QTqcmSs9ZLrmjNaoG29FyUFNY/mQIjLln6YbbEfY2CcQy6LDRHifL1sMo dxXoiLKpMKqj8DpPw7eBXwfZQ02cprRCKQvTzBpt7wfuxDN1K9GFm3YI1bji9r8V yyCKN1HdpBeOXBcLr1H4Khw0jXWNJyG/vi25KabBSm3hm0A8eIJPfpQkspTLdt5P dQYDXYMVseUClua+o19AYaFzUX8AHZE6fQK5TKJrb6cqFXx0vhCMClcyzyK0qP7X /1QRRXFPYuiKViWGlw+vLTb0rydS1u+kBAtZMzo9yxqR3Kl6Slk2gu3yRbUg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; t=1652945935; x=1653032335; bh=JlHqic7LqsBADopy3n3gr2qpLmBL iebZIJyqFqagYKc=; b=owvnYMGieG1v7FIEcpo1S/m91CnKUaFL4a2gIuM5ZAWK o+lStwp9WGOZLZMtWZ2HAbGVbDD6JlKDOu9WcXAVDDVcsh/fAMxzitYTVHwLdXwZ vqaCwJMQOb+7EFow2NtDMBWxkAJenyk5+2btsNeZqMc/fpiCIttInEu0HhpMOYJU 1dFXS16uR75hkmTwnb3pXa7h5Q+eHEB992UE8Ya3ja6fYu0ta4aNROmlHC9foPnQ HlzN5nDHDBpJ8i7bSeZFqMjH9+fZxb/Ei1yH22UhMRy0HydUitGBemrfStSM6Z8Y OxqtHFOo/jDmxG+SGrx4igixoB0gv7no61yytzf2pA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedriedtgdduvdegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpeffhffvvefukfhfgggtuggjsehttd ertddttddvnecuhfhrohhmpefirhgvghcumffjuceoghhrvghgsehkrhhorghhrdgtohhm qeenucggtffrrghtthgvrhhnpeehgedvvedvleejuefgtdduudfhkeeltdeihfevjeekje euhfdtueefhffgheekteenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgr ihhlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomh X-ME-Proxy: Feedback-ID: i787e41f1:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 19 May 2022 03:38:55 -0400 (EDT) Date: Thu, 19 May 2022 09:38:53 +0200 From: Greg KH To: Matt Silva Subject: Re: Supporting a USB HID device interface that is missing a interrupt input endpoint Message-ID: References: <1sT3lu7QxRdv6jrZycSEE8VsfPtAXiJNL5BBDBp-cMiTG3DbEau-NDI_mo8leikQo5u6KBwPS-mb_6sz0aja8idAVM5hMwg2oQ6dRzjJrXo=@protonmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: "kernelnewbies@kernelnewbies.org" X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org On Wed, May 18, 2022 at 10:04:14PM +0000, Matt Silva wrote: > Hi, Greg. Thanks for the response, I really appreciate it! Awesome to get a reply from the man himself. > > Probably wasn't the best from me to refer to the Windows software as a driver. As far as I can tell it > is just a userspace application using the Windows interface to communicate, as you described below. > > From my understanding, the device intends to operate as a HID device (unless your comment below about > all devices claiming to be HID when they're not on Windows applies here), it even provides a HID descriptor > with usages to Windows. It's also my understanding that for certain devices with "quirks" that don't > operate normally, the Linux kernel has quirks that allow these edge case devices to operate as intended. But this really is not a HID device, right? What is the HID descriptor that it prints out? Can you use the 'usbhid-dump' program that is part of the usbutils package to show the report descriptors? > So while your feedback about using libusb for OpenRGB in userspace definitely doable, I was curious if this device > would benifit from having support for its quirk added to the kernel so that it can be exposed in userspace > as it intends, rather than just solving my specific problem for OpenRGB. As far as I can tell, the > interface never communicated to directly through its single OUT endpoint. The communication is through > the control endpoint via a SET REPORT request. I did some reading and you are correct, HID class > interfaces require a interrupt in endpoint. But like I said, the fact that it only communicates via the > control endpoint made me think that maybe this requirement may not be necessary for the interface > to function as intended. If this is all going through a "fake" SET REPORT command, in a vendor-specific way, I would just recommend doing it all from userspace using libusb like OpenRGB does for other devices. No need to mess with the kernel at all for a fake HID device like this. good luck! greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies