Avoid unconditional context restore every time we gate uart
clocks. Check whether context loss happened based on which
we can context restore uart regs from uart_port structure.
Signed-off-by: Govindraj.R <govindraj.r...@ti.com>
---
arch/arm/mach-omap2/serial.c | 2 ++
arch/arm/plat-omap/include/plat/omap-serial.h | 3 +++
drivers/tty/serial/omap-serial.c | 20 ++++++++++++++++++--
3 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 06887d3..98e2666 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -33,6 +33,7 @@
#include <plat/dma.h>
#include <plat/omap_hwmod.h>
#include <plat/omap_device.h>
+#include <plat/omap-pm.h>
#include "prm2xxx_3xxx.h"
#include "pm.h"
@@ -478,6 +479,7 @@ void __init omap_serial_init_port(struct omap_board_data
*bdata)
omap_up.dma_enabled = uart->dma_enabled;
omap_up.uartclk = OMAP24XX_BASE_BAUD * 16;
omap_up.flags = UPF_BOOT_AUTOCONF;
+ omap_up.get_context_loss_count = omap_pm_get_dev_context_loss_count;
pdata = &omap_up;
pdata_size = sizeof(struct omap_uart_port_info);
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h
b/arch/arm/plat-omap/include/plat/omap-serial.h
index 5b913c7..348c9ea 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -62,6 +62,8 @@ struct omap_uart_port_info {
bool dma_enabled; /* To specify DMA Mode */
unsigned int uartclk; /* UART clock rate */
upf_t flags; /* UPF_* flags */
+
+ int (*get_context_loss_count)(struct device *);
};
struct uart_omap_dma {
@@ -114,6 +116,7 @@ struct uart_omap_port {
unsigned char msr_saved_flags;
char name[20];
unsigned long port_activity;
+ u32 context_loss_cnt;
};
#endif /* __OMAP_SERIAL_H__ */
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index f5a5ed6..ea4c24a 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1440,15 +1440,31 @@ static void serial_omap_restore_context(struct
uart_omap_port *up)
#ifdef CONFIG_PM_RUNTIME
static int serial_omap_runtime_suspend(struct device *dev)
{
+ struct uart_omap_port *up = dev_get_drvdata(dev);
+ struct omap_uart_port_info *pdata = dev->platform_data;
+
+ if (!up)
+ return -EINVAL;
+
+ if (pdata->get_context_loss_count)
+ up->context_loss_cnt = pdata->get_context_loss_count(dev);
+
return 0;
}
static int serial_omap_runtime_resume(struct device *dev)
{
struct uart_omap_port *up = dev_get_drvdata(dev);
+ struct omap_uart_port_info *pdata = dev->platform_data;
- if (up)
- serial_omap_restore_context(up);
+ if (up) {
+ if (pdata->get_context_loss_count) {
+ u32 loss_cnt = pdata->get_context_loss_count(dev);
+
+ if (up->context_loss_cnt != loss_cnt)
+ serial_omap_restore_context(up);
+ }
+ }
return 0;
}
--
1.7.4.1
--
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