From patchwork Sat Oct 24 12:14:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ioana Ciornei X-Patchwork-Id: 11854807 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=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 0A492C4363A for ; Sat, 24 Oct 2020 12:15:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCA112226B for ; Sat, 24 Oct 2020 12:15:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761254AbgJXMOl (ORCPT ); Sat, 24 Oct 2020 08:14:41 -0400 Received: from inva021.nxp.com ([92.121.34.21]:59766 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761233AbgJXMOj (ORCPT ); Sat, 24 Oct 2020 08:14:39 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id CD4C9200F10; Sat, 24 Oct 2020 14:14:35 +0200 (CEST) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id B5A19200F0F; Sat, 24 Oct 2020 14:14:35 +0200 (CEST) Received: from fsr-ub1864-126.ea.freescale.net (fsr-ub1864-126.ea.freescale.net [10.171.82.212]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 9B59F20347; Sat, 24 Oct 2020 14:14:34 +0200 (CEST) From: Ioana Ciornei To: Andrew Lunn , Heiner Kallweit , Russell King , Jakub Kicinski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ioana Ciornei , Alexandru Ardelean , Andre Edich , Antoine Tenart , Baruch Siach , Christophe Leroy , Dan Murphy , Divya Koppera , Florian Fainelli , Hauke Mehrtens , Jerome Brunet , Kavya Sree Kotagiri , Linus Walleij , Marco Felsch , Marek Vasut , Martin Blumenstingl , Mathias Kresin , Maxim Kochetkov , Michael Walle , Neil Armstrong , Nisar Sayed , Oleksij Rempel , Philippe Schenker , Willy Liu , Yuiko Oshino Subject: [RFC net-next 0/5] net: phy: add support for shared interrupts Date: Sat, 24 Oct 2020 15:14:07 +0300 Message-Id: <20201024121412.10070-1-ioana.ciornei@nxp.com> X-Mailer: git-send-email 2.17.1 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC This patch set aims to actually add support for shared interrupts in phylib and not only for multi-PHY devices. While we are at it, streamline the interrupt handling in phylib. For a bit of context, at the moment, there are multiple phy_driver ops that deal with this subject: - .config_intr() - Enable/disable the interrupt line. - .ack_interrupt() - Should quiesce any interrupts that may have been fired. It's also used by phylib in conjunction with .config_intr() to clear any pending interrupts after the line was disabled, and before it is going to be enabled. - .did_interrupt() - Intended for multi-PHY devices with a shared IRQ line and used by phylib to discern which PHY from the package was the one that actually fired the interrupt. - .handle_interrupt() - Completely overrides the default interrupt handling logic from phylib. The PHY driver is responsible for checking if any interrupt was fired by the respective PHY and choose accordingly if it's the one that should trigger the link state machine. From my point of view, the interrupt handling in phylib has become somewhat confusing with all these callbacks that actually read the same PHY register - the interrupt status. A more streamlined approach would be to just move the responsibility to write an interrupt handler to the driver (as any other device driver does) and make .handle_interrupt() the only way to deal with interrupts. Another advantage with this approach would be that phylib would gain support for shared IRQs between different PHY (not just multi-PHY devices), something which at the moment would require extending every PHY driver anyway in order to implement their .did_interrupt() callback and duplicate the same logic as in .ack_interrupt(). The disadvantage of making .did_interrupt() mandatory would be that we are slightly changing the semantics of the phylib API and that would increase confusion instead of reducing it. What I am proposing is the following: - As a first step, make the .ack_interrupt() callback optional so that we do not break any PHY driver amid the transition. - Every PHY driver gains a .handle_interrupt() implementation that, for the most part, would look like below: irq_status = phy_read(phydev, INTR_STATUS); if (irq_status < 0) { phy_error(phydev); return IRQ_NONE; } if (irq_status == 0) return IRQ_NONE; phy_trigger_machine(phydev); return IRQ_HANDLED; - Remove each PHY driver's implementation of the .ack_interrupt() by actually taking care of quiescing any pending interrupts before enabling/after disabling the interrupt line. - Finally, after all drivers have been ported, remove the .ack_interrupt() and .did_interrupt() callbacks from phy_driver. This RFC just contains the patches for phylib and a single driver - Atheros. The rest can be found on my Github branch here: TODO They will be submitted as a multi-part series once the merge window closes. I do not have access to most of these PHY's, therefore I Cc-ed the latest contributors to the individual PHY drivers in order to have access, hopefully, to more regression testing. Ioana Ciornei (5): net: phy: export phy_error and phy_trigger_machine net: phy: add a shutdown procedure net: phy: make .ack_interrupt() optional net: phy: at803x: implement generic .handle_interrupt() callback net: phy: at803x: remove the use of .ack_interrupt() drivers/net/phy/at803x.c | 42 ++++++++++++++++++++++++++++++------ drivers/net/phy/phy.c | 6 ++++-- drivers/net/phy/phy_device.c | 10 ++++++++- include/linux/phy.h | 2 ++ 4 files changed, 50 insertions(+), 10 deletions(-) Cc: Alexandru Ardelean Cc: Andre Edich Cc: Antoine Tenart Cc: Baruch Siach Cc: Christophe Leroy Cc: Dan Murphy Cc: Divya Koppera Cc: Florian Fainelli Cc: Hauke Mehrtens Cc: Heiner Kallweit Cc: Jerome Brunet Cc: Kavya Sree Kotagiri Cc: Linus Walleij Cc: Marco Felsch Cc: Marek Vasut Cc: Martin Blumenstingl Cc: Mathias Kresin Cc: Maxim Kochetkov Cc: Michael Walle Cc: Neil Armstrong Cc: Nisar Sayed Cc: Oleksij Rempel Cc: Philippe Schenker Cc: Willy Liu Cc: Yuiko Oshino