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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 6023BC2D0FA for ; Wed, 13 May 2020 11:17:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46EB62078C for ; Wed, 13 May 2020 11:17:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732289AbgEMLRZ (ORCPT ); Wed, 13 May 2020 07:17:25 -0400 Received: from foss.arm.com ([217.140.110.172]:43658 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730286AbgEMLRZ (ORCPT ); Wed, 13 May 2020 07:17:25 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9309830E; Wed, 13 May 2020 04:17:24 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E8C9C3F71E; Wed, 13 May 2020 04:17:22 -0700 (PDT) Date: Wed, 13 May 2020 12:17:17 +0100 From: Lorenzo Pieralisi To: Nicolas Saenz Julienne Cc: f.fainelli@gmail.com, gregkh@linuxfoundation.org, wahrenst@gmx.net, helgaas@kernel.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, tim.gover@raspberrypi.org, linux-pci@vger.kernel.org, Rob Herring Subject: Re: [PATCH v8 0/4] USB: pci-quirks: Add Raspberry Pi 4 quirk Message-ID: <20200513111717.GA32365@e121166-lin.cambridge.arm.com> References: <20200505161318.26200-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200505161318.26200-1-nsaenzjulienne@suse.de> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Tue, May 05, 2020 at 06:13:13PM +0200, Nicolas Saenz Julienne wrote: > On the Raspberry Pi 4, after a PCI reset, VL805's firmware may either be > loaded directly from an EEPROM or, if not present, by the SoC's > co-processor, VideoCore. This series adds support for the later. > > Note that there are a set of constraints we have to consider: > - We need to make sure the VideoCore firmware interface is up and > running before running the VL805 firmware load call. > > - There is no way to discern RPi4's VL805 chip from other platforms', > so we need the firmware load to happen *before* running > quirk_usb_handoff_xhci(). Failure to do so results in an unwarranted > 5 second wait while the fixup code polls xHC's non-existing state. > > By Florian's suggestion I've been spending some time exploring the device > link[1] API in order to see if that could save us from explicitly creating > probe dependencies between pcie-brcmstb and firmware/raspberrypi (patch #3). > Technically these dependencies could be inferred from DT. It turns out Saravana > Kannan has been looking at this already. A new boot mechanism, activated with > fw_devlink=on takes care of the device probe ordering on devices with > consumer/supplier relationships. For now this relationship is created based on > the usage of generic DT properties, but has no support for vendor-specifc DT > properties, which we'd be forced to use in order to create a relationship > between our two devices since our setup is highly non generic. There will > probably be at some point support for such properties, and we will then be able > to revisit some of this code. > > All this is based on the work by Tim Gover in RPi's downstream > kernel[2]. > > [1] https://www.kernel.org/doc/html/v4.13/driver-api/device_link.html > [2] https://github.com/raspberrypi/linux/commit/9935b4c7e360b4494b4cb6e3ce797238a1ab78bd > > --- > > Changes since v7: > - Address Stefan's comments > > Changes since v6: > - Make rpi_firmware_init_vl805() more robust > - Rewrite comments and patch descriptions to be more accessible to non RPi > fluent people > - Removed Florian's Reviewed-by in patch #2 as function changed > substantially > - Tested with/witout u-boot > > Changes since v5: > - Fix issues reported by Kbuild test robot > > Changes since v4: > - Addressed Sergei's comments > - Fix potential warning in patch #2 > > Changes since v3: > - Addressed Greg's comments > > There was no v2, my bad. > > Changes since v1: > - Addressed Floarians comments > > Nicolas Saenz Julienne (4): > soc: bcm2835: Add notify xHCI reset property > firmware: raspberrypi: Introduce vl805 init routine > PCI: brcmstb: Wait for Raspberry Pi's firmware when present > USB: pci-quirks: Add Raspberry Pi 4 quirk > > drivers/firmware/Kconfig | 3 +- > drivers/firmware/raspberrypi.c | 61 ++++++++++++++++++++++ > drivers/pci/controller/pcie-brcmstb.c | 17 ++++++ > drivers/usb/host/pci-quirks.c | 16 ++++++ > include/soc/bcm2835/raspberrypi-firmware.h | 9 +++- > 5 files changed, 104 insertions(+), 2 deletions(-) Hi Nicolas, should I queue this series via the PCI tree ? Just let me know, most of the changes are not in the PCI tree, asking in order to minimize/simplify conflicts handling if possible. Lorenzo