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[2620:137:e000::1:20]) by mx.google.com with ESMTP id j62-20020a638041000000b0051b5bb35d72si13349293pgd.338.2023.04.18.03.50.00; Tue, 18 Apr 2023 03:50:14 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=jFdJtxow; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231256AbjDRKkr (ORCPT + 99 others); Tue, 18 Apr 2023 06:40:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230307AbjDRKkq (ORCPT ); Tue, 18 Apr 2023 06:40:46 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A22D449D; Tue, 18 Apr 2023 03:40:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0417C62FEF; Tue, 18 Apr 2023 10:40:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C4B0C433EF; Tue, 18 Apr 2023 10:40:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681814444; bh=xDMKA9FoRNcqFbWL1PKwxfPqy4WBygGisOwZl5zE7Is=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jFdJtxow6kjLoGtpMzRNsQEcRYeZtKDxpr+YN8SCY3LpbqqWV24pgtFCBg0XwYXQP ZcDZ1ETAbE1K7I8zDBOF2Bnqrbgf//0tIzEBfMd/p6kQSbw9bq77PwV2+IKYpuKFYu M4m8HG7NuGM9fvUqpwGxgwCi/nXj5MIsJr30AmIM= Date: Tue, 18 Apr 2023 12:40:41 +0200 From: Greg KH To: Rajat Khandelwal Cc: heikki.krogerus@linux.intel.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] usb: typec: intel_pmc_mux: Expose IOM port status to debugfs Message-ID: <2023041845-eastcoast-precinct-3b8c@gregkh> References: <20230414081910.1336405-1-rajat.khandelwal@linux.intel.com> <2c960f0c-5cbb-4c2d-07cb-dafd94d22414@linux.intel.com> <20cc057d-6b2b-5fc1-524f-c2c579c96a6b@linux.intel.com> <2023041859-humpback-thespian-e28c@gregkh> <19c137ac-ac95-e6da-27d8-27d9cc8e9e40@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19c137ac-ac95-e6da-27d8-27d9cc8e9e40@linux.intel.com> X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 18, 2023 at 03:53:46PM +0530, Rajat Khandelwal wrote: > Hi, > > On 4/18/2023 3:48 PM, Greg KH wrote: > > On Tue, Apr 18, 2023 at 03:10:47PM +0530, Rajat Khandelwal wrote: > > > Hi, > > > > > > On 4/17/2023 11:42 AM, Greg KH wrote: > > > > On Mon, Apr 17, 2023 at 11:28:18AM +0530, Rajat Khandelwal wrote: > > > > > Hi, > > > > > > > > > > On 4/15/2023 11:01 AM, Greg KH wrote: > > > > > > On Fri, Apr 14, 2023 at 01:49:10PM +0530, Rajat Khandelwal wrote: > > > > > > > IOM status has a crucial role during debugging to check the > > > > > > > current state of the type-C port. > > > > > > > There are ways to fetch the status, but all those require the > > > > > > > IOM port status offset, which could change with platform. > > > > > > > > > > > > > > Make a debugfs directory for intel_pmc_mux and expose the status > > > > > > > under it per port basis. > > > > > > > > > > > > > > Signed-off-by: Rajat Khandelwal > > > > > > > --- > > > > > > > > > > > > > > v2: > > > > > > > 1. Remove static declaration of the debugfs root for 'intel_pmc_mux' > > > > > > > 2. Remove explicitly defined one-liner functions > > > > > > > > > > > > > > drivers/usb/typec/mux/intel_pmc_mux.c | 34 +++++++++++++++++++++++++++ > > > > > > > 1 file changed, 34 insertions(+) > > > > > > > > > > > > > > diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c > > > > > > > index 34e4188a40ff..1d43b111781e 100644 > > > > > > > --- a/drivers/usb/typec/mux/intel_pmc_mux.c > > > > > > > +++ b/drivers/usb/typec/mux/intel_pmc_mux.c > > > > > > > @@ -15,6 +15,7 @@ > > > > > > > #include > > > > > > > #include > > > > > > > #include > > > > > > > +#include > > > > > > > #include > > > > > > > @@ -639,9 +640,34 @@ static int pmc_usb_probe_iom(struct pmc_usb *pmc) > > > > > > > return 0; > > > > > > > } > > > > > > > +static int port_iom_status_show(struct seq_file *s, void *unused) > > > > > > > +{ > > > > > > > + struct pmc_usb_port *port = s->private; > > > > > > > + > > > > > > > + update_port_status(port); > > > > > > > + seq_printf(s, "0x%08x\n", port->iom_status); > > > > > > > + > > > > > > > + return 0; > > > > > > > +} > > > > > > > +DEFINE_SHOW_ATTRIBUTE(port_iom_status); > > > > > > > + > > > > > > > +static void pmc_mux_port_debugfs_init(struct pmc_usb_port *port, > > > > > > > + struct dentry *pmc_mux_debugfs_root) > > > > > > > +{ > > > > > > > + struct dentry *debugfs_dir; > > > > > > > + char name[6]; > > > > > > > + > > > > > > > + snprintf(name, sizeof(name), "port%d", port->usb3_port - 1); > > > > > > > + > > > > > > > + debugfs_dir = debugfs_create_dir(name, pmc_mux_debugfs_root); > > > > > > > + debugfs_create_file("iom_status", 0400, debugfs_dir, port, > > > > > > > + &port_iom_status_fops); > > > > > > > +} > > > > > > > + > > > > > > > static int pmc_usb_probe(struct platform_device *pdev) > > > > > > > { > > > > > > > struct fwnode_handle *fwnode = NULL; > > > > > > > + struct dentry *pmc_mux_debugfs_root; > > > > > > > struct pmc_usb *pmc; > > > > > > > int i = 0; > > > > > > > int ret; > > > > > > > @@ -674,6 +700,8 @@ static int pmc_usb_probe(struct platform_device *pdev) > > > > > > > if (ret) > > > > > > > return ret; > > > > > > > + pmc_mux_debugfs_root = debugfs_create_dir("intel_pmc_mux", NULL); > > > > > > What happens when you have more than one device in the system at the > > > > > > same time? > > > > > I'm sorry I didn't understand the question. We would have separate directories > > > > > for all the ports which would contain the 'iom_status' file, thus representing > > > > > status for all the ports individually. > > > > > Can you rephrase the question since I guess you had something else in mind? > > > > Can you please show the output of the directory > > > > /sys/kernel/debug/intel_pmc_mux/ with multiple pmc devices in the system > > > > at the same time? > > > Sorry, I don't own a system with multiple PMCs. Anyways, do we even have > > > a system with such design? > > You might tomorrow. So please don't create problems like this when you > > do not have to. > > We still didn't arrive on a culminating note. :) > What do you suggest I could do for now? This would be a useful debug tool > for us since we deal with it quite often. Then do it properly please. Look at the /sys/kernel/debug/usb/ directory for examples, specifically /sys/kernel/debug/xhci/. > If we don't have anything constraining this for now, can we keep it like > this? No.