OMAP2+: PM/serial: hold console semaphore while OMAP UARTs are disabled

Commit Message

Paul Walmsley Nov. 24, 2010, 11:49 p.m. UTC

None

Patch

diff --git a/arch/arm/mach-omap2/pm24xx.c b/arch/arm/mach-omap2/pm24xx.c
index a40457d..c85923e5 100644
--- a/arch/arm/mach-omap2/pm24xx.c
+++ b/arch/arm/mach-omap2/pm24xx.c
@@ -30,6 +30,7 @@ 
 #include <linux/irq.h>
 #include <linux/time.h>
 #include <linux/gpio.h>
+#include <linux/console.h>
 
 #include <asm/mach/time.h>
 #include <asm/mach/irq.h>
@@ -118,6 +119,10 @@  static void omap2_enter_full_retention(void)
 	if (omap_irq_pending())
 		goto no_sleep;
 
+	/* Block console output in case it is on one of the OMAP UARTs */
+	if (try_acquire_console_sem())
+		goto no_sleep;
+
 	omap_uart_prepare_idle(0);
 	omap_uart_prepare_idle(1);
 	omap_uart_prepare_idle(2);
@@ -131,6 +136,8 @@  static void omap2_enter_full_retention(void)
 	omap_uart_resume_idle(1);
 	omap_uart_resume_idle(0);
 
+	release_console_sem();
+
 no_sleep:
 	if (omap2_pm_debug) {
 		unsigned long long tmp;
diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c
index 75c0cd1..0ec8a04 100644
--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -28,6 +28,7 @@ 
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/console.h>
 
 #include <plat/sram.h>
 #include <plat/clockdomain.h>
@@ -385,6 +386,12 @@  void omap_sram_idle(void)
 		omap3_enable_io_chain();
 	}
 
+	/* Block console output in case it is on one of the OMAP UARTs */
+	if (per_next_state < PWRDM_POWER_ON ||
+	    core_next_state < PWRDM_POWER_ON)
+		if (try_acquire_console_sem())
+			goto console_still_active;
+
 	/* PER */
 	if (per_next_state < PWRDM_POWER_ON) {
 		omap_uart_prepare_idle(2);
@@ -463,6 +470,9 @@  void omap_sram_idle(void)
 		omap_uart_resume_idle(3);
 	}
 
+	release_console_sem();
+
+console_still_active:
 	/* Disable IO-PAD and IO-CHAIN wakeup */
 	if (omap3_has_io_wakeup() &&
 	    (per_next_state < PWRDM_POWER_ON ||
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index edd7c99..18935ea 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -27,6 +27,7 @@ 
 #include <linux/slab.h>
 #include <linux/serial_8250.h>
 #include <linux/pm_runtime.h>
+#include <linux/console.h>
 
 #ifdef CONFIG_SERIAL_OMAP
 #include <plat/omap-serial.h>
@@ -810,6 +811,8 @@  void __init omap_serial_init_port(int port)
 
 	oh->dev_attr = uart;
 
+	acquire_console_sem(); /* in case the earlycon is on the UART */
+
 	/*
 	 * Because of early UART probing, UART did not get idled
 	 * on init.  Now that omap_device is ready, ensure full idle
@@ -834,6 +837,8 @@  void __init omap_serial_init_port(int port)
 	omap_uart_block_sleep(uart);
 	uart->timeout = DEFAULT_TIMEOUT;
 
+	release_console_sem();
+
 	if ((cpu_is_omap34xx() && uart->padconf) ||
 	    (uart->wk_en && uart->wk_mask)) {
 		device_init_wakeup(&od->pdev.dev, true);