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 996FD3F1655; Fri, 8 May 2026 14:42:43 +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=1778251363; cv=none; b=GyNtXTLqgtIx++H6aK1hWuEkLLPRy8VJBS3roagPthxJfT+mwSUKuTTg7Uvz8uT2T/hT4sbx5xRvtFTdZ3nSGOqz6XWWgMNDbWPicDNXe8nnKlA5TcnRYF6g5Y37Tv8SBy0byJOM8CktHz0RJXWNLcQTwRoBT5EZAKzGs4wdoVI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778251363; c=relaxed/simple; bh=fwSulS9p2KQXubNlBUEZFPP7KWK+SXr/m+kU38386Lg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oK00x2W0b1ADERLFFlEZNsO/lwwSTvwPi0MpctJTlJfD2Cveg3Dr2y8wzASeJGTp/TFn1cElk/CmPS/l6FF4VK/hFjNiEPbHrA04ATqjJoEWUknN4y3/w1CvNjDyHtnJhqmxvOR0Lqr5iF2+2Zcfu0v80SIn9w2Al7IeUhkKNSI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WsQZBFLe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WsQZBFLe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11C6EC2BCB0; Fri, 8 May 2026 14:42:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778251363; bh=fwSulS9p2KQXubNlBUEZFPP7KWK+SXr/m+kU38386Lg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WsQZBFLeR0drDq6JjXEOYinHpoNdwDQkT/kh10BZUWebi+tLl9Z8iu5nFZylwmwG+ TBaB5ST59mT/d7BPBmr1Q3wP5LGT70jPOeN1/wJiuw8ZVrg6wXwbiJPLJLLwdWu+jy bhibDX+iVcbdO+gYPX2HBlYOgWRwZR2t1q72FM7GWtdWVcFpJfKW6XpUM7ppfICJFb qTQDKNFWKQGq43uk3n8o3BxEPSylc1JAaZKgI6T1AwIHUy1q1Mk9dLN21svGPwSY2U gt7m+C37Ijo2qlcXrclzL3fRlXnOcLhvqMGPx7vw1ZJFOV9KscV7c1p6gn01IBLBb4 JuVcu1fLr5HGg== Date: Fri, 8 May 2026 09:42:41 -0500 From: Bjorn Helgaas To: pawell@cadence.com Cc: Peter Chen , Roger Quadros , Greg Kroah-Hartman , Bjorn Helgaas , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v3] usb: cdnsp: Add support for device-only configuration Message-ID: <20260508144241.GC85390@bhelgaas> References: <20260508-no_drd_config-v3-1-0614f5044721@cadence.com> Precedence: bulk X-Mailing-List: linux-pci@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: <20260508-no_drd_config-v3-1-0614f5044721@cadence.com> On Fri, May 08, 2026 at 12:06:39PM +0200, Pawel Laszczak via B4 Relay wrote: > From: Pawel Laszczak > > This patch introduces support for the Cadence USBSSP (cdnsp) > controller in hardware configurations where the Dual-Role Device (DRD) > register block is not implemented or is inaccessible. > > In such cases, the driver cannot rely on the DRD logic to manage roles > and must operate exclusively in a fixed peripheral/host mode. > > The change in BAR indexing (from BAR 2 to BAR 1) is a direct > consequence of the 32-bit addressing used in this specific > DRD-disabled hardware layout, compared to the 64-bit addressing > used in DRD-enabled configurations. > > Tested on a PCI platform with a hardware configuration that lacks > DRD support. Platform-side changes are included to support the PCI > glue layer's property injection to handle this specific layout. > > Acked-by: Bjorn Helgaas # pci_ids.h I did ack this (https://lore.kernel.org/linux-pci/20260331181209.GA148250@bhelgaas/) but I wish I had added a note about why. Usually we don't add things to pci_ids.h unless they're used by more than one driver. This (slightly) simplifies backporting things. Fine as-is, but if you respin for other reasons, you could consider moving it to cdnsp-pci.c. > +++ b/include/linux/pci_ids.h * Do not add new entries to this file unless the definitions * are shared between multiple drivers. */ > +#define PCI_DEVICE_ID_CDNS_UDC_USBSSP 0x0400 Looks like this #define could go in cdnsp-pci.c, since that's the only place it's used.