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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 34CD5C433E2 for ; Tue, 2 Jun 2020 18:55:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C64C20734 for ; Tue, 2 Jun 2020 18:55:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726977AbgFBSzV (ORCPT ); Tue, 2 Jun 2020 14:55:21 -0400 Received: from muru.com ([72.249.23.125]:56784 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbgFBSzU (ORCPT ); Tue, 2 Jun 2020 14:55:20 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 5EB0680C5; Tue, 2 Jun 2020 18:56:09 +0000 (UTC) Date: Tue, 2 Jun 2020 11:55:15 -0700 From: Tony Lindgren To: Andy Shevchenko Cc: Johan Hovold , Peter Hurley , Greg Kroah-Hartman , Vignesh Raghavendra , "open list:SERIAL DRIVERS" , Linux OMAP Mailing List , Linux Kernel Mailing List , Andy Shevchenko , Merlijn Wajer , Pavel Machek , Sebastian Reichel , "Rafael J. Wysocki" Subject: Re: [PATCH] serial: 8250_port: Fix imprecise external abort for mctrl if inactive Message-ID: <20200602185515.GF37466@atomide.com> References: <20200602001813.30459-1-tony@atomide.com> <20200602080811.GI19480@localhost> <20200602133659.GD37466@atomide.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200602133659.GD37466@atomide.com> Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org * Tony Lindgren [200602 13:38]: > * Andy Shevchenko [200602 08:33]: > Now that we can detach and reattach the kernel serial console, > there should not be any need for pm_runtime_irq_safe() anymore :) Below is a hastily tested RFC patch to remove pm_runtime_irq_safe() for 8250_omap.c that seems to work for idle use case :) > And the UART wake-up from deeper idle states can only happen with > help of external hardware like GPIO controller or pinctrl controller. It does not yet include the check for configured wakeirq though. And omap-serial.c needs a similar patch or maybe we can attempt to just drop it this time as 8250_omap.c should be used nowadays. Or just drop PM from omap-serial.c if it can't be dropped. Andy, is the change below the only remaining blocker now for your serial PM runtime changes? Regards, Tony 8< ------------------------------- diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -123,6 +123,7 @@ struct omap8250_priv { spinlock_t rx_dma_lock; bool rx_dma_broken; bool throttled; + unsigned int active:1; }; struct omap8250_dma_params { @@ -598,9 +599,13 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) { struct uart_port *port = dev_id; struct uart_8250_port *up = up_to_u8250p(port); + struct omap8250_priv *priv = up->port.private_data; unsigned int iir; int ret; + if (!priv->active) + return IRQ_NONE; + #ifdef CONFIG_SERIAL_8250_DMA if (up->dma) { ret = omap_8250_dma_handle_irq(port); @@ -608,10 +613,10 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) } #endif - serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); - serial8250_rpm_put(up); + + pm_runtime_mark_last_busy(port->dev); return IRQ_RETVAL(ret); } @@ -1110,13 +1115,9 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) unsigned long flags; u8 iir; - serial8250_rpm_get(up); - iir = serial_port_in(port, UART_IIR); - if (iir & UART_IIR_NO_INT) { - serial8250_rpm_put(up); + if (iir & UART_IIR_NO_INT) return IRQ_HANDLED; - } spin_lock_irqsave(&port->lock, flags); @@ -1144,7 +1145,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) } uart_unlock_and_check_sysrq(port, flags); - serial8250_rpm_put(up); + return 1; } @@ -1329,11 +1330,10 @@ static int omap8250_probe(struct platform_device *pdev) if (!of_get_available_child_count(pdev->dev.of_node)) pm_runtime_set_autosuspend_delay(&pdev->dev, -1); - pm_runtime_irq_safe(&pdev->dev); - pm_runtime_get_sync(&pdev->dev); omap_serial_fill_features_erratas(&up, priv); + priv->active = pm_runtime_enabled(&pdev->dev); up.port.handle_irq = omap8250_no_handle_irq; priv->rx_trigger = RX_TRIGGER; priv->tx_trigger = TX_TRIGGER; @@ -1517,6 +1517,8 @@ static int omap8250_runtime_suspend(struct device *dev) if (!priv) return 0; + priv->active = 0; + up = serial8250_get_port(priv->line); /* * When using 'no_console_suspend', the console UART must not be @@ -1575,6 +1577,8 @@ static int omap8250_runtime_resume(struct device *dev) pinctrl_pm_select_default_state(dev); + priv->active = 1; + return 0; } #endif -- 2.26.2