From patchwork Tue Sep 21 10:33:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 12507567 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 382D8C433F5 for ; Tue, 21 Sep 2021 10:34:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24C8161038 for ; Tue, 21 Sep 2021 10:34:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232060AbhIUKfi (ORCPT ); Tue, 21 Sep 2021 06:35:38 -0400 Received: from muru.com ([72.249.23.125]:35568 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232076AbhIUKfe (ORCPT ); Tue, 21 Sep 2021 06:35:34 -0400 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 11D6E812F; Tue, 21 Sep 2021 10:34:31 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman Cc: Andy Shevchenko , Jiri Slaby , Johan Hovold , Vignesh Raghavendra , linux-serial@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/6] serial: 8250_omap: Drop the use of pm_runtime_irq_safe() Date: Tue, 21 Sep 2021 13:33:46 +0300 Message-Id: <20210921103346.64824-7-tony@atomide.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210921103346.64824-1-tony@atomide.com> References: <20210921103346.64824-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We already have the serial layer RX wake path fixed for power management. We no longer allow deeper idle states unless the kernel console has been detached, and we require that the RX wakeirq is configured. For TX path, we may have the serial port autoidled, and need to wake it up before writing to it. With the serial_core prep_tx() changes, we can finally drop the dependency to pm_runtime_irq_safe() for 8250_omap driver. To drop pm_runtime_irq_safe(), we remove all PM runtime calls from the interrupt context. If we ever see an interrupt for an idled port, we just bail out. We now also need to restore the port context with interrupts disabled to prevent interrupts from happening while restoring the port. Signed-off-by: Tony Lindgren --- drivers/tty/serial/8250/8250_omap.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) 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 @@ -134,6 +134,7 @@ struct omap8250_priv { bool rx_dma_broken; bool throttled; unsigned int allow_rpm:1; + unsigned int clocks_off:1; }; struct omap8250_dma_params { @@ -621,6 +622,9 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) unsigned int iir, lsr; int ret; + if (priv->clocks_off) + return IRQ_NONE; + #ifdef CONFIG_SERIAL_8250_DMA if (up->dma) { ret = omap_8250_dma_handle_irq(port); @@ -628,7 +632,6 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) } #endif - serial8250_rpm_get(up); lsr = serial_port_in(port, UART_LSR); iir = serial_port_in(port, UART_IIR); ret = serial8250_handle_irq(port, iir); @@ -662,8 +665,6 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id) schedule_delayed_work(&up->overrun_backoff, delay); } - serial8250_rpm_put(up); - return IRQ_RETVAL(ret); } @@ -1191,13 +1192,9 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) unsigned char status; 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(&port->lock); @@ -1226,7 +1223,6 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) uart_unlock_and_check_sysrq(port); - serial8250_rpm_put(up); return 1; } @@ -1420,8 +1416,6 @@ 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); @@ -1637,6 +1631,8 @@ static int omap8250_runtime_suspend(struct device *dev) omap_8250_rx_dma_flush(up); priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; + priv->clocks_off = 1; + schedule_work(&priv->qos_work); return 0; @@ -1646,13 +1642,18 @@ static int omap8250_runtime_resume(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); struct uart_8250_port *up; + struct uart_port *port; + unsigned long flags; /* In case runtime-pm tries this before we are setup */ if (!priv) return 0; up = serial8250_get_port(priv->line); + port = &up->port; + /* Restore state with interrupts disabled */ + spin_lock_irqsave(&port->lock, flags); if (omap8250_lost_context(up)) omap8250_restore_regs(up); @@ -1660,6 +1661,9 @@ static int omap8250_runtime_resume(struct device *dev) omap_8250_rx_dma(up); priv->latency = priv->calc_latency; + priv->clocks_off = 0; + spin_unlock_irqrestore(&port->lock, flags); + schedule_work(&priv->qos_work); return 0; }