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 A701D2BE051; Mon, 5 Jan 2026 19:59:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767643147; cv=none; b=l7uS41GYuZjXmkk42a21vA7RbzpKs9EebK8gvFPOWjB5BZC7aJpYlXYU/RegSh89dn/dt1Pbvv26kkK4BXg/IcOjgnssPjjMOFiiG3/k6A29DGDr1iXLl1lf4T9pIpTfGObhz/JqntUcI2gEnuvEsHORzLKOsyjaFo5wP1JJSv4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767643147; c=relaxed/simple; bh=cRaS5r3lgkI/yPdjV2VtjiMfycKB0unfFxQ5VsEkHGs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MUc7UgdC8n16w4ukCv/dRn5Y4IhQd5q1GRBdK8yVUn2kTfH6ZLWxAm9J/WgQbpub+M4k3/S+7uLh2ePH8VEf0Hx4HfQ6GcqnTkYpbDyflSbk8E8fGoVHO0wSJiCaRwYjRR81lcqA2oSgHSWKjC/tsxl8lyc5s3vbSB6H82kCLvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=o3P1qXUa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="o3P1qXUa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5642C116D0; Mon, 5 Jan 2026 19:59:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767643147; bh=cRaS5r3lgkI/yPdjV2VtjiMfycKB0unfFxQ5VsEkHGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=o3P1qXUayEhhRve+eqKN/vQ/4NXgOaAW1TW4Bb6VwhBcvBnw6sH9yyaSt+y3rpGRi /FTWvtBziJsUg+chAt4VVxoPFxq1gBmg7wtcIP6a5dwPsAWNP7ljK7DUFZdZU2V1w/ 2gy0njFsKwbn3O6hRlvqmvltMu/HbWOki4EQt0V8= Date: Mon, 5 Jan 2026 20:59:04 +0100 From: Greg Kroah-Hartman To: Thinh Nguyen Cc: Prashanth K , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 0/3] Add the DWC3 instance name in traces Message-ID: <2026010513-kinsman-moody-6d63@gregkh> References: <20260105115325.1765176-1-prashanth.k@oss.qualcomm.com> <2026010555-squealing-easily-7659@gregkh> <20260105161145.podzns57ekzjg3pj@synopsys.com> <2026010528-animal-avenging-dad2@gregkh> <20260105170044.vuuoyiszyptokmfp@synopsys.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: <20260105170044.vuuoyiszyptokmfp@synopsys.com> On Mon, Jan 05, 2026 at 05:01:00PM +0000, Thinh Nguyen wrote: > On Mon, Jan 05, 2026, Greg Kroah-Hartman wrote: > > On Mon, Jan 05, 2026 at 04:11:50PM +0000, Thinh Nguyen wrote: > > > Hi Greg, > > > > > > On Mon, Jan 05, 2026, Greg Kroah-Hartman wrote: > > > > On Mon, Jan 05, 2026 at 05:23:22PM +0530, Prashanth K wrote: > > > > > When multiple DWC3 controllers are being used, trace events from > > > > > different instances get mixed up making debugging difficult as > > > > > there's no way to distinguish which instance generated the trace. > > > > > > > > > > Hence append the controller base address into ftrace. This needs > > > > > the following reworks which is addressed using this patch series. > > > > > > > > > > 1. Removal of dep->regs and use dwc->regs everywhere > > > > > 2. Use dwc pointer in all dwc3_readl/writel() > > > > > 3. Adding the base addr in traces. > > > > > > > > > > Changes in v2: > > > > > - Avoid using macros for dwc3_readl/writel() > > > > > - Use base address intraces instead of dev name. > > > > > > > > Wait, why change this? The dev name is what you should care about. > > > > "base address" doesn't make much sense as this is on a lot of different > > > > busses, right? > > > > > > > > > > I asked Prashanth to do so. The reason is because the device name is not > > > consistent and not obvious for different busses. For example, for PCI > > > devices, the device name may be in a form of "dwc3.N.auto". If we only > > > have access to the traces and not the testing setup (which often is the > > > case), it's difficult to tell which is which. Also, very often the > > > consumer of the traces is also the hardware validation engineer, and > > > IMO, it's more understandable reading base address than device name. > > > > But all you need to know is "this is different than the other one", you > > don't "need" the io address, right? And if you really did, just add > > that to the trace as well _when_ you actually need it. > > The base address preserves that context to know which instance is which. > If we have the base address, do we still need the device name? If you have only the "base address", how do you know which device is which? thanks, greg k-h