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serial: 8250_omap: Drop pm_runtime_irq_safe()

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Let's drop the use of pm_runtime_irq_safe() for 8250_omap. The use of
pm_runtime_irq_safe() is not nice as it takes a permanent usage count on
the parent device.

We can finally drop pm_runtime_irq_safe() safely as the kernel now knows
when the uart port tx is active. This changed with commit 84a9582fd2
("serial: core: Start managing serial controllers to enable runtime PM").

For serial port rx, we already use Linux generic wakeirqs for 8250_omap.

To drop pm_runtime_irq_safe(), we need to add handling for shallow idle
state where the port hardware may already be awake and an IO interrupt
happens. We also need to replace the serial8250_rpm sync calls in the
interrupt handlers with async runtime PM calls.

Note that omap8250_irq() calls omap_8250_dma_handle_irq(), so we don't
need separate runtime PM calls in omap_8250_dma_handle_irq().

While at it, let's also add the missing line break to the end of
omap8250_runtime_resume() to group the calls.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231004062650.64487-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tony Lindgren 2023-10-04 09:26:48 +03:00 committed by Greg Kroah-Hartman
parent b9cbe7e8f2
commit 8700a7ea55
1 changed files with 21 additions and 8 deletions
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29
drivers/tty/serial/8250/8250_omap.c
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@ -8,6 +8,7 @@
*
*/
#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/io.h>
@ -130,6 +131,7 @@ struct omap8250_priv {
u8 tx_trigger;
u8 rx_trigger;
atomic_t active;
bool is_suspending;
int wakeirq;
int wakeups_enabled;
@ -632,14 +634,23 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
unsigned int iir, lsr;
int ret;
pm_runtime_get_noresume(port->dev);
/* Shallow idle state wake-up to an IO interrupt? */
if (atomic_add_unless(&priv->active, 1, 1)) {
priv->latency = priv->calc_latency;
schedule_work(&priv->qos_work);
}
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
ret = omap_8250_dma_handle_irq(port);
pm_runtime_mark_last_busy(port->dev);
pm_runtime_put(port->dev);
return IRQ_RETVAL(ret);
}
#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);
@ -676,7 +687,8 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
schedule_delayed_work(&up->overrun_backoff, delay);
}
serial8250_rpm_put(up);
pm_runtime_mark_last_busy(port->dev);
pm_runtime_put(port->dev);
return IRQ_RETVAL(ret);
}
@ -1270,11 +1282,8 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
u16 status;
u8 iir;
serial8250_rpm_get(up);
iir = serial_port_in(port, UART_IIR);
if (iir & UART_IIR_NO_INT) {
serial8250_rpm_put(up);
return IRQ_HANDLED;
}
@ -1305,7 +1314,6 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
uart_unlock_and_check_sysrq(port);
serial8250_rpm_put(up);
return 1;
}
@ -1503,8 +1511,6 @@ 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);
@ -1748,6 +1754,7 @@ static int omap8250_runtime_suspend(struct device *dev)
priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
schedule_work(&priv->qos_work);
atomic_set(&priv->active, 0);
return 0;
}
@ -1757,6 +1764,10 @@ static int omap8250_runtime_resume(struct device *dev)
struct omap8250_priv *priv = dev_get_drvdata(dev);
struct uart_8250_port *up = NULL;
/* Did the hardware wake to a device IO interrupt before a wakeirq? */
if (atomic_read(&priv->active))
return 0;
if (priv->line >= 0)
up = serial8250_get_port(priv->line);
@ -1772,8 +1783,10 @@ static int omap8250_runtime_resume(struct device *dev)
uart_port_unlock_irq(&up->port);
}
atomic_set(&priv->active, 1);
priv->latency = priv->calc_latency;
schedule_work(&priv->qos_work);
return 0;
}