[PATCH 2/8] OMAP3 PM: Conditional UART context save restore.

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Currently UART context save is done in idle
thread thru a call to omap_uart_prepare_idle irrespective of
what power state is attained by the power domain to which
the UART belongs to. This patch allows omap_uart_prepare_idle
to take power state as a parameter and this function in
turn does a uart context save only if the passed power state
is PWRDM_POWER_OFF. In the restore path a restore will
happen only if a valid save has happened.

Signed-off-by: Thara Gopinath <thara@xxxxxx>
---
 arch/arm/mach-omap2/pm34xx.c             |    6 +++---
 arch/arm/mach-omap2/serial.c             |   17 +++++++----------
 arch/arm/plat-omap/include/plat/serial.h |    2 +-
 3 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 8f5e819..895e9ef 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -418,7 +418,7 @@ void omap_sram_idle(void)
 			} else
 				omap3_per_save_context();
 		}
-		omap_uart_prepare_idle(2);
+		omap_uart_prepare_idle(2, per_next_state);
 	}
 
 	if (pwrdm_read_pwrst(cam_pwrdm) == PWRDM_POWER_ON)
@@ -435,8 +435,8 @@ void omap_sram_idle(void)
 
 	/* CORE */
 	if (core_next_state < PWRDM_POWER_ON) {
-		omap_uart_prepare_idle(0);
-		omap_uart_prepare_idle(1);
+		omap_uart_prepare_idle(0, core_next_state);
+		omap_uart_prepare_idle(1, core_next_state);
 		if (core_next_state == PWRDM_POWER_OFF) {
 			u32 voltctrl = OMAP3430_AUTO_OFF;
 
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 837b347..fb59d5f 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -168,9 +168,6 @@ static void omap_uart_save_context(struct omap_uart_state *uart)
 	u16 lcr = 0;
 	struct plat_serial8250_port *p = uart->p;
 
-	if (!enable_off_mode)
-		return;
-
 	lcr = serial_read_reg(p, UART_LCR);
 	serial_write_reg(p, UART_LCR, 0xBF);
 	uart->dll = serial_read_reg(p, UART_DLL);
@@ -189,9 +186,6 @@ static void omap_uart_restore_context(struct omap_uart_state *uart)
 	u16 efr = 0;
 	struct plat_serial8250_port *p = uart->p;
 
-	if (!enable_off_mode)
-		return;
-
 	if (!uart->context_valid)
 		return;
 
@@ -235,12 +229,15 @@ static inline void omap_uart_enable_clocks(struct omap_uart_state *uart)
 
 #ifdef CONFIG_PM
 
-static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
+static inline void omap_uart_disable_clocks(struct omap_uart_state *uart,
+							int power_state)
 {
 	if (!uart->clocked)
 		return;
 
-	omap_uart_save_context(uart);
+	if (power_state == PWRDM_POWER_OFF)
+		omap_uart_save_context(uart);
+
 	uart->clocked = 0;
 	clk_disable(uart->ick);
 	clk_disable(uart->fck);
@@ -329,13 +326,13 @@ static void omap_uart_idle_timer(unsigned long data)
 	omap_uart_allow_sleep(uart);
 }
 
-void omap_uart_prepare_idle(int num)
+void omap_uart_prepare_idle(int num, int power_state)
 {
 	struct omap_uart_state *uart;
 
 	list_for_each_entry(uart, &uart_list, node) {
 		if (num == uart->num && uart->can_sleep) {
-			omap_uart_disable_clocks(uart);
+			omap_uart_disable_clocks(uart, power_state);
 			return;
 		}
 	}
diff --git a/arch/arm/plat-omap/include/plat/serial.h b/arch/arm/plat-omap/include/plat/serial.h
index f5a4a92..ca76742 100644
--- a/arch/arm/plat-omap/include/plat/serial.h
+++ b/arch/arm/plat-omap/include/plat/serial.h
@@ -57,7 +57,7 @@ extern void omap_serial_init_port(int port);
 extern int omap_uart_can_sleep(void);
 extern void omap_uart_check_wakeup(void);
 extern void omap_uart_prepare_suspend(void);
-extern void omap_uart_prepare_idle(int num);
+extern void omap_uart_prepare_idle(int num, int power_state);
 extern void omap_uart_resume_idle(int num);
 extern void omap_uart_enable_irqs(int enable);
 #endif
-- 
1.5.6.3

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