common: adc/i2c: Mark task_waiting volatile

When Link Time Optimization is turned on, functions that set
task_waiting multiple times have one of the sets removed
by the linker leading to undesired results.

Marking task_waiting volatile alleviates this issue.

BUG=chrome-os-partner:46063
TEST=Manually tested on Kunimitsu.
         Console command adc shows correct value of approx
         20000 mV for VBUS.
BRANCH=none

Change-Id: I85a6e5c9688ae72c45d90fb58296f94b74a301aa
Signed-off-by: Shamile Khan <shamile.khan@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/314233
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

7 files changed, 9 insertions, 11 deletions

diff --git a/board/kunimitsu/board.h b/board/kunimitsu/board.h
index b32b851d2f..dd50bcb86b 100644
--- a/board/kunimitsu/board.h
+++ b/board/kunimitsu/board.h
@@ -52,11 +52,7 @@
 #define CONFIG_LED_COMMON
 #define CONFIG_LID_SWITCH
 #define CONFIG_LOW_POWER_IDLE
-/*
- * TODO: Issue is seen with LTO feature, further debug is needed.
- *
 #define CONFIG_LTO
- */
 #define CONFIG_POWER_BUTTON
 #define CONFIG_POWER_BUTTON_X86
 #define CONFIG_POWER_COMMON
diff --git a/chip/it83xx/i2c.c b/chip/it83xx/i2c.c
index d2aac92604..bc10a5970f 100644
--- a/chip/it83xx/i2c.c
+++ b/chip/it83xx/i2c.c
@@ -137,7 +137,7 @@ struct i2c_port_data {
 
 	enum i2c_ch_status i2ccs;
 	/* Task waiting on port, or TASK_ID_INVALID if none. */
-	int task_waiting;
+	volatile int task_waiting;
 };
 static struct i2c_port_data pdata[I2C_PORT_COUNT];
 
diff --git a/chip/lm4/adc.c b/chip/lm4/adc.c
index 69338c61b0..40d5b3770d 100644
--- a/chip/lm4/adc.c
+++ b/chip/lm4/adc.c
@@ -21,7 +21,7 @@
 /* Maximum time we allow for an ADC conversion */
 #define ADC_TIMEOUT_US SECOND
 
-static task_id_t task_waiting_on_ss[LM4_ADC_SEQ_COUNT];
+static volatile task_id_t task_waiting_on_ss[LM4_ADC_SEQ_COUNT];
 
 static void configure_gpio(void)
 {
diff --git a/chip/lm4/i2c.c b/chip/lm4/i2c.c
index 9f3db7426f..6f3efb700e 100644
--- a/chip/lm4/i2c.c
+++ b/chip/lm4/i2c.c
@@ -65,7 +65,7 @@ struct i2c_port_data {
 	uint32_t timeout_us;	/* Transaction timeout, or 0 to use default */
 
 	/* Task waiting on port, or TASK_ID_INVALID if none. */
-	int task_waiting;
+	volatile int task_waiting;
 };
 static struct i2c_port_data pdata[I2C_PORT_COUNT];
 
diff --git a/chip/mec1322/adc.c b/chip/mec1322/adc.c
index 037f270428..841c3c7e32 100644
--- a/chip/mec1322/adc.c
+++ b/chip/mec1322/adc.c
@@ -21,7 +21,7 @@
 
 struct mutex adc_lock;
 
-static task_id_t task_waiting;
+static volatile task_id_t task_waiting;
 
 static int start_single_and_wait(int timeout)
 {
@@ -69,8 +69,10 @@ int adc_read_all_channels(int *data)
 	for (i = 0; i < ADC_CH_COUNT; ++i)
 		MEC1322_ADC_SINGLE |= 1 << adc_channels[i].channel;
 
-	if (!start_single_and_wait(ADC_SINGLE_READ_TIME * ADC_CH_COUNT))
+	if (!start_single_and_wait(ADC_SINGLE_READ_TIME * ADC_CH_COUNT)) {
+		ret = EC_ERROR_TIMEOUT;
 		goto exit_all_channels;
+	}
 
 	for (i = 0; i < ADC_CH_COUNT; ++i) {
 		adc = adc_channels + i;
diff --git a/chip/mec1322/i2c.c b/chip/mec1322/i2c.c
index a800e9e780..5a0cc850cb 100644
--- a/chip/mec1322/i2c.c
+++ b/chip/mec1322/i2c.c
@@ -55,7 +55,7 @@ struct {
 	/* Transaction timeout, or 0 to use default. */
 	uint32_t timeout_us;
 	/* Task waiting on port, or TASK_ID_INVALID if none. */
-	task_id_t task_waiting;
+	volatile task_id_t task_waiting;
 } cdata[I2C_CONTROLLER_COUNT];
 
 static void configure_controller_speed(int controller, int kbps)
diff --git a/chip/npcx/adc.c b/chip/npcx/adc.c
index ba80162f45..24a866c2a9 100644
--- a/chip/npcx/adc.c
+++ b/chip/npcx/adc.c
@@ -34,7 +34,7 @@ enum npcx_adc_conversion_mode {
 };
 
 /* Global variables */
-static task_id_t task_waiting;
+static volatile task_id_t task_waiting;
 
 /**
  * Preset ADC operation clock.