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authorSantosh Shilimkar <santosh.shilimkar@ti.com>2010-10-11 11:05:18 +0000
committerTony Lindgren <tony@atomide.com>2010-10-11 10:53:48 -0700
commita1b04cc197e17c47b043051becb548dc8c60c886 (patch)
treed8d5a1aaa0aef32e3c986493a7673d49c6ba169c /arch/arm/mach-omap2/serial.c
parentde65815860f187cb43551bc833bf9d72720faa01 (diff)
downloadop-kernel-dev-a1b04cc197e17c47b043051becb548dc8c60c886.zip
op-kernel-dev-a1b04cc197e17c47b043051becb548dc8c60c886.tar.gz
omap: serial: Fix the boot-up crash/reboot without CONFIG_PM
The omap2plus_defconfig doesn't boot up when built with CONFIG_PM disabled on the latest linux-omap master. Below are the observations 1. OMAP3 reboots in the middle of boot -------------------------------------------------- [ 0.000000] Calibrating delay loop... 494.72 BogoMIPS (lpj=1933312) [ 0.000000] pid_max: default: 32768 minimum: 301 [ 0.000000] Security Framework initialized [ 0.000000] Mount-cache hash table entries: 512 [ 0.000000] CPU: Testing write buffer coherency: ok [ 0.000000] Brought up 1 CPUs [ 0.000000] SMP: Total of 1 processors activated (494.72 BogoMIPS). [ 0.000000] regulator: core version 0.5 [ 0.000000] NET: Registered protocol family 16 U-Boot 1.1.4 (Feb 11 2009 - 16:10:23) OMAP3430-GP rev 2, CPU-OPP2 L3-165MHz TI 3430SDP 1.0 Version + mDDR (Boot NOR) DRAM: 128 MB Flash: 128 MB NAND:128 MiB -------------------------------------------------- 2. OMAP4 does a kernel PANIC ------------------------------------- [ 0.000000] Calibrating delay loop... 1195.29 BogoMIPS (lpj=4669440) [ 0.000000] pid_max: default: 32768 minimum: 301 [ 0.000000] Security Framework initialized [ 0.000000] Mount-cache hash table entries: 512 [ 0.000000] CPU: Testing write buffer coherency: ok [ 0.000000] L310 cache controller enabled [ 0.000000] l2x0: 16 ways, CACHE_ID 0x410000c2, AUX_CTRL 0x0e050000 [ 0.000000] CPU1: Booted secondary processor [ 0.000000] Brought up 2 CPUs [ 0.000000] SMP: Total of 2 processors activated (2395.78 BogoMIPS). [ 0.000000] regulator: core version 0.5 [ 0.000000] NET: Registered protocol family 16 [ 0.000000] mux: Could not set signal i2c2_scl.i2c2_scl [ 0.000000] mux: Could not set signal i2c2_sda.i2c2_sda [ 0.000000] mux: Could not set signal i2c3_scl.i2c3_scl [ 0.000000] mux: Could not set signal i2c3_sda.i2c3_sda [ 0.000000] mux: Could not set signal i2c4_scl.i2c4_scl [ 0.000000] mux: Could not set signal i2c4_sda.i2c4_sda ------------------------------------- This is happening because 'omap_serial_init()' is hanging in the boot. On OMAP3 the watchdog is generating reboot because devices_init doesn't happens where as on OMAP4 it just hangs without reboot. The uart clock is not getting enabled after omap_device_idle as part of omap_serial_init. The omap_device_idle(will disable the clock) then omap_uart_block_sleep() should enable clock back disabled during the boot up phase. But omap_uart_block_sleep() stuffed version is binded only under CONFIG_PM and other version is just empty. Hence it is not enabling clock back as expected This patch adds uart clock enable code to omap_uart_block_sleep() function built with CONFIG_PM disabled. Thanks to Charulatha and Govindraj for their help on this debug. Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Charulatha V <charu@ti.com> Signed-off-by: Govindraj.R <govindraj.raja@ti.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm/mach-omap2/serial.c')
-rw-r--r--arch/arm/mach-omap2/serial.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 338e46a..ba8a5cc 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -608,7 +608,11 @@ static DEVICE_ATTR(sleep_timeout, 0644, sleep_timeout_show,
#define DEV_CREATE_FILE(dev, attr) WARN_ON(device_create_file(dev, attr))
#else
static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
-static void omap_uart_block_sleep(struct omap_uart_state *uart) {}
+static void omap_uart_block_sleep(struct omap_uart_state *uart)
+{
+ /* Needed to enable UART clocks when built without CONFIG_PM */
+ omap_uart_enable_clocks(uart);
+}
#define DEV_CREATE_FILE(dev, attr)
#endif /* CONFIG_PM */
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