From patchwork Mon May 8 08:20:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 13234228 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 818C7C77B7F for ; Mon, 8 May 2023 08:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233613AbjEHIUg (ORCPT ); Mon, 8 May 2023 04:20:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232438AbjEHIUf (ORCPT ); Mon, 8 May 2023 04:20:35 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1FD471AEF2; Mon, 8 May 2023 01:20:30 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id BB2998121; Mon, 8 May 2023 08:20:27 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby , Peter Hurley , Sebastian Andrzej Siewior Cc: Andy Shevchenko , Dhruva Gole , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Johan Hovold , Vignesh Raghavendra , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/4] serial: 8250: omap: Fix freeing of resources on failed register Date: Mon, 8 May 2023 11:20:11 +0300 Message-Id: <20230508082014.23083-2-tony@atomide.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508082014.23083-1-tony@atomide.com> References: <20230508082014.23083-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org If serial8250_register_8250_port() fails, the SoC can hang as the deferred PMQoS work will still run as is not flushed and removed. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren Reviewed-by: Ilpo Järvinen --- drivers/tty/serial/8250/8250_omap.c | 2 ++ 1 file changed, 2 insertions(+) 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 @@ -1532,7 +1532,9 @@ static int omap8250_probe(struct platform_device *pdev) err: pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); + flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); + cpu_latency_qos_remove_request(&priv->pm_qos_request); return ret; } From patchwork Mon May 8 08:20:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 13234229 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 012D3C7EE2A for ; Mon, 8 May 2023 08:20:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229999AbjEHIUh (ORCPT ); Mon, 8 May 2023 04:20:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233587AbjEHIUg (ORCPT ); Mon, 8 May 2023 04:20:36 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 414521C0CC; Mon, 8 May 2023 01:20:35 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 1174781BC; Mon, 8 May 2023 08:20:32 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , Dhruva Gole , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/4] serial: 8250: omap: Fix imprecise external abort for omap_8250_pm() Date: Mon, 8 May 2023 11:20:12 +0300 Message-Id: <20230508082014.23083-3-tony@atomide.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508082014.23083-1-tony@atomide.com> References: <20230508082014.23083-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We must idle the uart only after serial8250_unregister_port(). Otherwise unbinding the uart via sysfs while doing cat on the port produces an imprecise external abort: mem_serial_in from omap_8250_pm+0x44/0xf4 omap_8250_pm from uart_hangup+0xe0/0x194 uart_hangup from __tty_hangup.part.0+0x37c/0x3a8 __tty_hangup.part.0 from uart_remove_one_port+0x9c/0x22c uart_remove_one_port from serial8250_unregister_port+0x60/0xe8 serial8250_unregister_port from omap8250_remove+0x6c/0xd0 omap8250_remove from platform_remove+0x28/0x54 Turns out the driver needs to have runtime PM functional before the driver probe calls serial8250_register_8250_port(). And it needs runtime PM after driver remove calls serial8250_unregister_port(). On probe, we need to read registers before registering the port in omap_serial_fill_features_erratas(). We do that with custom uart_read() already. On remove, after serial8250_unregister_port(), we need to write to the uart registers to idle the device. Let's add a custom uart_write() for that. Currently the uart register access depends on port->membase to be initialized, which won't work after serial8250_unregister_port(). Let's use priv->membase instead, and use it for runtime PM related functions to remove the dependency to port->membase for early and late register access. Note that during use, we need to check for a valid port in the runtime PM related functions. This is needed for the optional wakeup configuration. We now need to set the drvdata a bit earlier so it's available for the runtime PM functions. With the port checks in runtime PM functions, the old checks for priv in omap8250_runtime_suspend() and omap8250_runtime_resume() functions are no longer needed and are removed. Signed-off-by: Tony Lindgren --- drivers/tty/serial/8250/8250_omap.c | 70 ++++++++++++++++------------- 1 file changed, 38 insertions(+), 32 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 @@ -32,6 +32,7 @@ #include "8250.h" #define DEFAULT_CLK_SPEED 48000000 +#define OMAP_UART_REGSHIFT 2 #define UART_ERRATA_i202_MDR1_ACCESS (1 << 0) #define OMAP_UART_WER_HAS_TX_WAKEUP (1 << 1) @@ -115,6 +116,7 @@ #define UART_OMAP_RX_LVL 0x19 struct omap8250_priv { + void __iomem *membase; int line; u8 habit; u8 mdr1; @@ -159,9 +161,14 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p); static inline void omap_8250_rx_dma_flush(struct uart_8250_port *p) { } #endif -static u32 uart_read(struct uart_8250_port *up, u32 reg) +static u32 uart_read(struct omap8250_priv *priv, u32 reg) { - return readl(up->port.membase + (reg << up->port.regshift)); + return readl(priv->membase + (reg << OMAP_UART_REGSHIFT)); +} + +static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val) +{ + writel(val, priv->membase + (reg << OMAP_UART_REGSHIFT)); } /* @@ -548,7 +555,7 @@ static void omap_serial_fill_features_erratas(struct uart_8250_port *up, u32 mvr, scheme; u16 revision, major, minor; - mvr = uart_read(up, UART_OMAP_MVER); + mvr = uart_read(priv, UART_OMAP_MVER); /* Check revision register scheme */ scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT; @@ -1394,7 +1401,7 @@ static int omap8250_probe(struct platform_device *pdev) UPF_HARD_FLOW; up.port.private_data = priv; - up.port.regshift = 2; + up.port.regshift = OMAP_UART_REGSHIFT; up.port.fifosize = 64; up.tx_loadsz = 64; up.capabilities = UART_CAP_FIFO; @@ -1457,6 +1464,8 @@ static int omap8250_probe(struct platform_device *pdev) DEFAULT_CLK_SPEED); } + priv->membase = membase; + priv->line = -ENODEV; priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; priv->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; cpu_latency_qos_add_request(&priv->pm_qos_request, priv->latency); @@ -1464,6 +1473,8 @@ static int omap8250_probe(struct platform_device *pdev) spin_lock_init(&priv->rx_dma_lock); + platform_set_drvdata(pdev, priv); + device_init_wakeup(&pdev->dev, true); pm_runtime_enable(&pdev->dev); pm_runtime_use_autosuspend(&pdev->dev); @@ -1525,7 +1536,6 @@ static int omap8250_probe(struct platform_device *pdev) goto err; } priv->line = ret; - platform_set_drvdata(pdev, priv); pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); return 0; @@ -1547,11 +1557,12 @@ static int omap8250_remove(struct platform_device *pdev) if (err) return err; + serial8250_unregister_port(priv->line); + priv->line = -ENODEV; pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); - serial8250_unregister_port(priv->line); cpu_latency_qos_remove_request(&priv->pm_qos_request); device_init_wakeup(&pdev->dev, false); return 0; @@ -1627,7 +1638,6 @@ static int omap8250_lost_context(struct uart_8250_port *up) static int omap8250_soft_reset(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); - struct uart_8250_port *up = serial8250_get_port(priv->line); int timeout = 100; int sysc; int syss; @@ -1641,20 +1651,20 @@ static int omap8250_soft_reset(struct device *dev) * needing omap8250_soft_reset() quirk. Do it in two writes as * recommended in the comment for omap8250_update_scr(). */ - serial_out(up, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1); - serial_out(up, UART_OMAP_SCR, + uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1); + uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL); - sysc = serial_in(up, UART_OMAP_SYSC); + sysc = uart_read(priv, UART_OMAP_SYSC); /* softreset the UART */ sysc |= OMAP_UART_SYSC_SOFTRESET; - serial_out(up, UART_OMAP_SYSC, sysc); + uart_write(priv, UART_OMAP_SYSC, sysc); /* By experiments, 1us enough for reset complete on AM335x */ do { udelay(1); - syss = serial_in(up, UART_OMAP_SYSS); + syss = uart_read(priv, UART_OMAP_SYSS); } while (--timeout && !(syss & OMAP_UART_SYSS_RESETDONE)); if (!timeout) { @@ -1668,13 +1678,10 @@ static int omap8250_soft_reset(struct device *dev) static int omap8250_runtime_suspend(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); - struct uart_8250_port *up; + struct uart_8250_port *up = NULL; - /* In case runtime-pm tries this before we are setup */ - if (!priv) - return 0; - - up = serial8250_get_port(priv->line); + if (priv->line >= 0) + up = serial8250_get_port(priv->line); /* * When using 'no_console_suspend', the console UART must not be * suspended. Since driver suspend is managed by runtime suspend, @@ -1682,7 +1689,7 @@ static int omap8250_runtime_suspend(struct device *dev) * active during suspend. */ if (priv->is_suspending && !console_suspend_enabled) { - if (uart_console(&up->port)) + if (up && uart_console(&up->port)) return -EBUSY; } @@ -1693,13 +1700,15 @@ static int omap8250_runtime_suspend(struct device *dev) if (ret) return ret; - /* Restore to UART mode after reset (for wakeup) */ - omap8250_update_mdr1(up, priv); - /* Restore wakeup enable register */ - serial_out(up, UART_OMAP_WER, priv->wer); + if (up) { + /* Restore to UART mode after reset (for wakeup) */ + omap8250_update_mdr1(up, priv); + /* Restore wakeup enable register */ + serial_out(up, UART_OMAP_WER, priv->wer); + } } - if (up->dma && up->dma->rxchan) + if (up && up->dma && up->dma->rxchan) omap_8250_rx_dma_flush(up); priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; @@ -1711,18 +1720,15 @@ static int omap8250_runtime_suspend(struct device *dev) static int omap8250_runtime_resume(struct device *dev) { struct omap8250_priv *priv = dev_get_drvdata(dev); - struct uart_8250_port *up; + struct uart_8250_port *up = NULL; - /* In case runtime-pm tries this before we are setup */ - if (!priv) - return 0; + if (priv->line >= 0) + up = serial8250_get_port(priv->line); - up = serial8250_get_port(priv->line); - - if (omap8250_lost_context(up)) + if (up && omap8250_lost_context(up)) omap8250_restore_regs(up); - if (up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) + if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) omap_8250_rx_dma(up); priv->latency = priv->calc_latency; From patchwork Mon May 8 08:20:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 13234230 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76F0BC77B7F for ; Mon, 8 May 2023 08:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233710AbjEHIUs (ORCPT ); Mon, 8 May 2023 04:20:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233658AbjEHIUn (ORCPT ); Mon, 8 May 2023 04:20:43 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 49C0E1E98E; Mon, 8 May 2023 01:20:41 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 198178111; Mon, 8 May 2023 08:20:38 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , Dhruva Gole , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] serial: 8250: omap: Fix life cycle issues for interrupt handlers Date: Mon, 8 May 2023 11:20:13 +0300 Message-Id: <20230508082014.23083-4-tony@atomide.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508082014.23083-1-tony@atomide.com> References: <20230508082014.23083-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org We have the struct uart_8250_port instance recycled on device rebind while the struct omap8250_priv instance is not. For the console uart, __tty_hangup() does not call tty->ops->hangup() as cons_filp stays open, and uart shutdown won't get called. This means we have a stale priv->wakeirq handler around after unbind, and port->irq is not freed on unbind. There's no need to claim the interrupts on startup. We can fix this and simplify the driver a bit by claiming the interrupts in probe, and clearing them on remove. For the device interrupt, we can use devm_request_irq(). To do this, we change omap8250_irq() to use struct omap8250_priv data directly so we don't have to wait for the assigned port from serial8250_register_8250_port(). We must also drop IRQF_SHARED to set IRQ_NOAUTOEN to avoid spurious interrupts until the port has been registered. There's no need for IRQF_SHARED for 8250_omap, the serial port interrupt lines are dedicated lines. Signed-off-by: Tony Lindgren --- drivers/tty/serial/8250/8250_omap.c | 33 ++++++++++++++--------------- 1 file changed, 16 insertions(+), 17 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 @@ -623,9 +623,9 @@ static int omap_8250_dma_handle_irq(struct uart_port *port); static irqreturn_t omap8250_irq(int irq, void *dev_id) { - struct uart_port *port = dev_id; - struct omap8250_priv *priv = port->private_data; - struct uart_8250_port *up = up_to_u8250p(port); + struct omap8250_priv *priv = dev_id; + struct uart_8250_port *up = serial8250_get_port(priv->line); + struct uart_port *port = &up->port; unsigned int iir, lsr; int ret; @@ -709,11 +709,6 @@ static int omap_8250_startup(struct uart_port *port) } } - ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED, - dev_name(port->dev), port); - if (ret < 0) - goto err; - up->ier = UART_IER_RLSI | UART_IER_RDI; serial_out(up, UART_IER, up->ier); @@ -730,14 +725,11 @@ static int omap_8250_startup(struct uart_port *port) if (up->dma && !(priv->habit & UART_HAS_EFR2)) up->dma->rx_dma(up); + enable_irq(up->port.irq); + pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); return 0; -err: - pm_runtime_mark_last_busy(port->dev); - pm_runtime_put_autosuspend(port->dev); - dev_pm_clear_wake_irq(port->dev); - return ret; } static void omap_8250_shutdown(struct uart_port *port) @@ -757,6 +749,8 @@ static void omap_8250_shutdown(struct uart_port *port) up->ier = 0; serial_out(up, UART_IER, 0); + disable_irq_nosync(up->port.irq); + dev_pm_clear_wake_irq(port->dev); if (up->dma) serial8250_release_dma(up); @@ -770,8 +764,6 @@ static void omap_8250_shutdown(struct uart_port *port) pm_runtime_mark_last_busy(port->dev); pm_runtime_put_autosuspend(port->dev); - free_irq(port->irq, port); - dev_pm_clear_wake_irq(port->dev); } static void omap_8250_throttle(struct uart_port *port) @@ -1451,8 +1443,6 @@ static int omap8250_probe(struct platform_device *pdev) &up.overrun_backoff_time_ms) != 0) up.overrun_backoff_time_ms = 0; - priv->wakeirq = irq_of_parse_and_map(np, 1); - pdata = of_device_get_match_data(&pdev->dev); if (pdata) priv->habit |= pdata->habit; @@ -1530,6 +1520,15 @@ static int omap8250_probe(struct platform_device *pdev) } } #endif + + irq_set_status_flags(irq, IRQ_NOAUTOEN); + ret = devm_request_irq(&pdev->dev, irq, omap8250_irq, 0, + dev_name(&pdev->dev), priv); + if (ret < 0) + return ret; + + priv->wakeirq = irq_of_parse_and_map(np, 1); + ret = serial8250_register_8250_port(&up); if (ret < 0) { dev_err(&pdev->dev, "unable to register 8250 port\n"); From patchwork Mon May 8 08:20:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 13234231 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 542F7C77B7F for ; Mon, 8 May 2023 08:21:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233237AbjEHIVH (ORCPT ); Mon, 8 May 2023 04:21:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45544 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233655AbjEHIUz (ORCPT ); Mon, 8 May 2023 04:20:55 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id CB4401F4BF; Mon, 8 May 2023 01:20:46 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 675FD8111; Mon, 8 May 2023 08:20:44 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , Dhruva Gole , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-omap@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] serial: 8250: omap: Shut down on remove for console uart Date: Mon, 8 May 2023 11:20:14 +0300 Message-Id: <20230508082014.23083-5-tony@atomide.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508082014.23083-1-tony@atomide.com> References: <20230508082014.23083-1-tony@atomide.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org When unbinding the console uart, we want to power down the uart hardware on remove. For the console uart, the normal shutdown path will never get called as the cons_filp stays open. Let's rearrange the dma related functions a bit so we can call driver shutdown also on console uart rebind. Currently we set up->dma on probe, but that causes issues calling omap_8250_shutdown() on remove. The dma startup will not get called on the next rebind as we still have up->dma set from probe. Note that serial8250_release_dma() already checks for dma so we can remove the check for it in 8205_omap driver. With these changes we also avoid hogging dma virtual channels for the unused uarts that may be limited on some devices. Signed-off-by: Tony Lindgren --- drivers/tty/serial/8250/8250_omap.c | 36 ++++++++++++++++------------- 1 file changed, 20 insertions(+), 16 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 @@ -679,6 +679,7 @@ static int omap_8250_startup(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = port->private_data; + struct uart_8250_dma *dma = &priv->omap8250_dma; int ret; if (priv->wakeirq) { @@ -697,16 +698,16 @@ static int omap_8250_startup(struct uart_port *port) up->msr_saved_flags = 0; /* Disable DMA for console UART */ - if (uart_console(port)) - up->dma = NULL; - - if (up->dma) { + if (dma->fn && !uart_console(port)) { + up->dma = &priv->omap8250_dma; ret = serial8250_request_dma(up); if (ret) { dev_warn_ratelimited(port->dev, "failed to request DMA\n"); up->dma = NULL; } + } else { + up->dma = NULL; } up->ier = UART_IER_RLSI | UART_IER_RDI; @@ -752,8 +753,8 @@ static void omap_8250_shutdown(struct uart_port *port) disable_irq_nosync(up->port.irq); dev_pm_clear_wake_irq(port->dev); - if (up->dma) - serial8250_release_dma(up); + serial8250_release_dma(up); + up->dma = NULL; /* * Disable break condition and FIFOs @@ -1499,24 +1500,24 @@ static int omap8250_probe(struct platform_device *pdev) ret = of_property_count_strings(np, "dma-names"); if (ret == 2) { struct omap8250_dma_params *dma_params = NULL; + struct uart_8250_dma *dma = &priv->omap8250_dma; - up.dma = &priv->omap8250_dma; - up.dma->fn = the_no_dma_filter_fn; - up.dma->tx_dma = omap_8250_tx_dma; - up.dma->rx_dma = omap_8250_rx_dma; + dma->fn = the_no_dma_filter_fn; + dma->tx_dma = omap_8250_tx_dma; + dma->rx_dma = omap_8250_rx_dma; if (pdata) dma_params = pdata->dma_params; if (dma_params) { - up.dma->rx_size = dma_params->rx_size; - up.dma->rxconf.src_maxburst = dma_params->rx_trigger; - up.dma->txconf.dst_maxburst = dma_params->tx_trigger; + dma->rx_size = dma_params->rx_size; + dma->rxconf.src_maxburst = dma_params->rx_trigger; + dma->txconf.dst_maxburst = dma_params->tx_trigger; priv->rx_trigger = dma_params->rx_trigger; priv->tx_trigger = dma_params->tx_trigger; } else { - up.dma->rx_size = RX_TRIGGER; - up.dma->rxconf.src_maxburst = RX_TRIGGER; - up.dma->txconf.dst_maxburst = TX_TRIGGER; + dma->rx_size = RX_TRIGGER; + dma->rxconf.src_maxburst = RX_TRIGGER; + dma->txconf.dst_maxburst = TX_TRIGGER; } } #endif @@ -1550,12 +1551,15 @@ static int omap8250_probe(struct platform_device *pdev) static int omap8250_remove(struct platform_device *pdev) { struct omap8250_priv *priv = platform_get_drvdata(pdev); + struct uart_8250_port *up; int err; err = pm_runtime_resume_and_get(&pdev->dev); if (err) return err; + up = serial8250_get_port(priv->line); + omap_8250_shutdown(&up->port); serial8250_unregister_port(priv->line); priv->line = -ENODEV; pm_runtime_dont_use_autosuspend(&pdev->dev);