From: Tony Lindgren <tony@atomide.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Johan Hovold <johan@kernel.org>,
Peter Hurley <peter@hurleysoftware.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Vignesh Raghavendra <vigneshr@ti.com>,
"open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Merlijn Wajer <merlijn@wizzup.org>, Pavel Machek <pavel@ucw.cz>,
Sebastian Reichel <sre@kernel.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH] serial: 8250_port: Fix imprecise external abort for mctrl if inactive
Date: Tue, 2 Jun 2020 11:55:15 -0700 [thread overview]
Message-ID: <20200602185515.GF37466@atomide.com> (raw)
In-Reply-To: <20200602133659.GD37466@atomide.com>
* Tony Lindgren <tony@atomide.com> [200602 13:38]:
> * Andy Shevchenko <andy.shevchenko@gmail.com> [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
next prev parent reply other threads:[~2020-06-02 18:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 0:18 [PATCH] serial: 8250_port: Fix imprecise external abort for mctrl if inactive Tony Lindgren
2020-06-02 8:08 ` Johan Hovold
2020-06-02 8:31 ` Andy Shevchenko
2020-06-02 13:36 ` Tony Lindgren
2020-06-02 18:55 ` Tony Lindgren [this message]
2020-06-15 9:57 ` Andy Shevchenko
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