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author | 2023-10-04 09:26:48 +0300 | |
---|---|---|
committer | 2023-10-05 09:41:22 +0200 | |
commit | 8700a7ea5519fb0b3bad2362adfeac358c2119ce (patch) | |
tree | 231c7b0f80f2415c9381dd43c0be932bb287ad73 /drivers/tty | |
parent | serial: 8250: Check for valid console index (diff) | |
download | linux-8700a7ea5519fb0b3bad2362adfeac358c2119ce.tar.gz linux-8700a7ea5519fb0b3bad2362adfeac358c2119ce.tar.bz2 linux-8700a7ea5519fb0b3bad2362adfeac358c2119ce.zip |
serial: 8250_omap: Drop pm_runtime_irq_safe()
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 84a9582fd203
("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>
Diffstat (limited to 'drivers/tty')
-rw-r--r-- | drivers/tty/serial/8250/8250_omap.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 9ea38e2a6e23..1192207d2321 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -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; } |