ARM: OMAP2+: UART: Remove omap_uart_can_sleep and add pm_qos
Omap_uart_can_sleep function blocks system wide low power state until
uart is active remove this func and add qos requests to prevent
MPU from transitioning.
Keep qos request to default value which will allow MPU to transition
and while uart baud rate is available calculate the latency value
from the baudrate and use the same to hold constraint while uart clocks
are enabled, and if uart is auto-idled the constraint is updated with
default constraint value allowing MPU to transition.
Qos requests are blocking notifier calls so put these requests to
work queue, also the driver uses irq_safe version of runtime API's
and callbacks can be called in interrupt disabled context.
So to avoid warn on slow path warning while using qos update
API's from runtime callbacks use the qos_work_queue.
During bootup the runtime_resume call backs might not be called and runtime
callback gets called only after uart is idled by setting the autosuspend
timeout. So qos_request from runtime resume callback might not activated during
boot if uart baudrate is calculated during bootup for console uart, so schedule
the qos_work queue once we calc_latency while configuring the uart port.
Flush and complete any pending qos jobs in work queue while suspending.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index e20332f..3a9d2b8 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -30,7 +30,6 @@
#include <plat/irqs.h>
#include "powerdomain.h"
#include "clockdomain.h"
-#include <plat/serial.h>
#include "pm.h"
#include "control.h"
@@ -245,11 +244,6 @@
struct omap3_idle_statedata *cx;
int ret;
- if (!omap3_can_sleep()) {
- new_state_idx = drv->safe_state_index;
- goto select_state;
- }
-
/*
* Prevent idle completely if CAM is active.
* CAM does not have wakeup capability in OMAP3.
diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c
index 22af2f2..b8822f8 100644
--- a/arch/arm/mach-omap2/pm24xx.c
+++ b/arch/arm/mach-omap2/pm24xx.c
@@ -222,8 +222,6 @@
{
if (omap2_fclks_active())
return 0;
- if (!omap_uart_can_sleep())
- return 0;
if (osc_ck->usecount > 1)
return 0;
if (omap_dma_running())
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 4feee45..4ee5f4e 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -35,7 +35,6 @@
#include <plat/sram.h>
#include "clockdomain.h"
#include "powerdomain.h"
-#include <plat/serial.h>
#include <plat/sdrc.h>
#include <plat/prcm.h>
#include <plat/gpmc.h>
@@ -456,21 +455,11 @@
clkdm_allow_idle(mpu_pwrdm->pwrdm_clkdms[0]);
}
-int omap3_can_sleep(void)
-{
- if (!omap_uart_can_sleep())
- return 0;
- return 1;
-}
-
static void omap3_pm_idle(void)
{
local_irq_disable();
local_fiq_disable();
- if (!omap3_can_sleep())
- goto out;
-
if (omap_irq_pending() || need_resched())
goto out;
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index c909770e..247d894 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -82,28 +82,6 @@
};
#ifdef CONFIG_PM
-
-int omap_uart_can_sleep(void)
-{
- struct omap_uart_state *uart;
- int can_sleep = 1;
-
- list_for_each_entry(uart, &uart_list, node) {
- if (!uart->clocked)
- continue;
-
- if (!uart->can_sleep) {
- can_sleep = 0;
- continue;
- }
-
- /* This UART can now safely sleep. */
- omap_uart_allow_sleep(uart);
- }
-
- return can_sleep;
-}
-
static void omap_uart_enable_wakeup(struct platform_device *pdev, bool enable)
{
struct omap_device *od = to_omap_device(pdev);
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index ea63b2b..9ff4444 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -19,6 +19,7 @@
#include <linux/serial_core.h>
#include <linux/platform_device.h>
+#include <linux/pm_qos.h>
#include <plat/mux.h>
@@ -130,6 +131,11 @@
u32 context_loss_cnt;
u32 errata;
u8 wakeups_enabled;
+
+ struct pm_qos_request pm_qos_request;
+ u32 latency;
+ u32 calc_latency;
+ struct work_struct qos_work;
};
#endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index e1eaa66..f3ff0ca 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -51,6 +51,8 @@
static int serial_omap_start_rxdma(struct uart_omap_port *up);
static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
+static struct workqueue_struct *serial_omap_uart_wq;
+
static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
{
offset <<= up->port.regshift;
@@ -671,6 +673,14 @@
serial_out(up, UART_LCR, up->lcr);
}
+static void serial_omap_uart_qos_work(struct work_struct *work)
+{
+ struct uart_omap_port *up = container_of(work, struct uart_omap_port,
+ qos_work);
+
+ pm_qos_update_request(&up->pm_qos_request, up->latency);
+}
+
static void
serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
@@ -711,6 +721,12 @@
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
quot = serial_omap_get_divisor(port, baud);
+ /* calculate wakeup latency constraint */
+ up->calc_latency = (1000000 * up->port.fifosize) /
+ (1000 * baud / 8);
+ up->latency = up->calc_latency;
+ schedule_work(&up->qos_work);
+
up->dll = quot & 0xff;
up->dlh = quot >> 8;
up->mdr1 = UART_OMAP_MDR1_DISABLE;
@@ -1145,8 +1161,11 @@
{
struct uart_omap_port *up = dev_get_drvdata(dev);
- if (up)
+ if (up) {
uart_suspend_port(&serial_omap_reg, &up->port);
+ flush_work_sync(&up->qos_work);
+ }
+
return 0;
}
@@ -1383,6 +1402,13 @@
up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
}
+ up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
+ up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
+ pm_qos_add_request(&up->pm_qos_request,
+ PM_QOS_CPU_DMA_LATENCY, up->latency);
+ serial_omap_uart_wq = create_singlethread_workqueue(up->name);
+ INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
+
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev,
omap_up_info->autosuspend_timeout);
@@ -1416,6 +1442,8 @@
if (up) {
pm_runtime_disable(&up->pdev->dev);
uart_remove_one_port(&serial_omap_reg, &up->port);
+ pm_qos_remove_request(&up->pm_qos_request);
+
kfree(up);
}
@@ -1518,6 +1546,9 @@
(up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
pdata->set_forceidle(up->pdev);
+ up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
+ schedule_work(&up->qos_work);
+
return 0;
}
@@ -1538,6 +1569,9 @@
if (up->use_dma && pdata->set_noidle &&
(up->errata & UART_ERRATA_i291_DMA_FORCEIDLE))
pdata->set_noidle(up->pdev);
+
+ up->latency = up->calc_latency;
+ schedule_work(&up->qos_work);
}
return 0;