Commit fef4f600 authored by Tony Lindgren's avatar Tony Lindgren Committed by Greg Kroah-Hartman
Browse files

serial: 8250: omap: Fix life cycle issues for interrupt handlers 



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: default avatarTony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230508082014.23083-4-tony@atomide.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 398cecc2

drivers/tty/serial/8250/8250_omap.c

+16 −17
Original line number Diff line number Diff line
@@ -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");