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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 814B9C35646 for ; Fri, 21 Feb 2020 12:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B1A42073A for ; Fri, 21 Feb 2020 12:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582289277; bh=IjGS++0eyMo56akWPTSH0jQLlkTZPME/xQRqFwkYxEU=; h=Date:From:To:cc:Subject:In-Reply-To:References:List-ID:From; b=qLSMt/uKwzmbY3zsHTyY1sn4OaJ82Q0EyOi9MpV80f8xl39IEsYx5Udr2KVVhkwfG LLEFvyChSbptzme2H/KPcYzHps9OOqgjsr5mKvSMnyi5wJb0ollbAWEElVaTbcvmOM 70YtnjiROUuBzebtBTUDmj9BAtpXdGzrz+MA/aUU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728295AbgBUMrx (ORCPT ); Fri, 21 Feb 2020 07:47:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:36140 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728264AbgBUMrv (ORCPT ); Fri, 21 Feb 2020 07:47:51 -0500 Received: from pobox.suse.cz (prg-ext-pat.suse.com [213.151.95.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D01532073A; Fri, 21 Feb 2020 12:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582289270; bh=IjGS++0eyMo56akWPTSH0jQLlkTZPME/xQRqFwkYxEU=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=yN0iLx15+zPqqBUBgZMkMjooRfOh33CVkPjS/hK2tYcHXIz7cqVO5MIdFReWGEA8X shVPME33fsj4D3VFw5+Rz9CXkTI7y6N/VC5MtHhlSiYqAkOL91/pVuxwVJVuu8Muos ioP3HK5GesdNg5E85FBKy66nEGqnT8/zrMcjzJfQ= Date: Fri, 21 Feb 2020 13:47:38 +0100 (CET) From: Jiri Kosina To: "Shah, Nehal-bakulchandra" cc: Benjamin Tissoires , Srinivas Pandruvada , Hans de Goede , Sandeep Singh , lkml , "open list:HID CORE LAYER" , Jonathan Cameron , linux-iio@vger.kernel.org, Shyam-sundar.S-k@amd.com Subject: Re: [PATCH v3 0/5] SFH: Add Support for AMD Sensor Fusion Hub In-Reply-To: <79506ad3-5172-be36-cecc-19d97bfa8b36@amd.com> Message-ID: References: <1581476197-25854-1-git-send-email-Sandeep.Singh@amd.com> <1ce6f591-1e8b-8291-7f18-48876fd70e10@redhat.com> <719b929927ce76dd7dda3a48319b5798aced591a.camel@linux.intel.com> <7a9b6f51-ef50-9078-325c-28e8cd17c182@amd.com> <79506ad3-5172-be36-cecc-19d97bfa8b36@amd.com> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Wed, 19 Feb 2020, Shah, Nehal-bakulchandra wrote: > > 2 problems here: > > - patch 3/5 references this debugfs interface which is only added in 4/5. > > - you are creating a new sysfs set of file for debug purpose only, but > > as soon as we start shipping those, some other people will find it > > more convenient to use that directly instead or IIO, and you won't be > > able to change anything there. > > > > So I would strongly advocate against having this debugfs, and suggest you to: > > - either keep this debugfs as a downstream patch > > - either play with eBPF or kprobes to retrieve the same information > > without changing the kernel. > > > > For reference, I recently tried to replicate the hidraw functionality > > with eBPF[0] without changing the kernel code, and it was working. > > Well, there was no filtering on the source of the HID event, but > > still, I got the same data directly from the kernel just by adding > > instrumentation in a couple of functions. Wow. Complete eBPF supremacy is really coming shortly apparently :) > If Jiri is Ok, then we will push the next patch as per suggestion here > i.e. taking out debugfs. I agree with that. Thanks, -- Jiri Kosina SUSE Labs