deac/osd-contiki
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

cc2538: lpm: Fix RTIMER_NOW() upon wake-up

Browse source 
When returning from PM1/2, the sleep timer value (used by RTIMER_NOW()) is not
up-to-date until a positive edge on the 32-kHz clock has been detected after the
system clock restarted. To ensure an updated value is read, wait for a positive
transition on the 32-kHz clock by polling the SYS_CTRL_CLOCK_STA.SYNC_32K bit,
before reading the sleep timer value.

Because of this RTIMER_NOW() fixup, lpm_exit() has to be called at the very
beginning of ISRs waking up the SoC. This also ensures that all clocks and
timers are enabled at the correct frequency and updated before using them
following wake-up.

Without this fix, etimers could sometimes (randomly, depending on timings)
become ultra slow (observed from 10x to 40x slower than normal) if the system
exited PM1/2 very often. This issue occurred more often with PM1.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
This commit is contained in:
Benoît Thébaudeau 2013-12-03 19:16:24 +01:00
parent f149197aa8
commit 5261bb861d
4 changed files with 31 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

16
cpu/cc2538/dev/gpio.c
View file

@ -83,10 +83,10 @@ notify(uint8_t mask, uint8_t port)
void
gpio_port_a_isr()
{
ENERGEST_ON(ENERGEST_TYPE_IRQ);
lpm_exit();
ENERGEST_ON(ENERGEST_TYPE_IRQ);
notify(REG(GPIO_A_BASE | GPIO_MIS), GPIO_A_NUM);
GPIO_CLEAR_INTERRUPT(GPIO_A_BASE, 0xFF);
@ -99,10 +99,10 @@ gpio_port_a_isr()
void
gpio_port_b_isr()
{
ENERGEST_ON(ENERGEST_TYPE_IRQ);
lpm_exit();
ENERGEST_ON(ENERGEST_TYPE_IRQ);
notify(REG(GPIO_B_BASE | GPIO_MIS), GPIO_B_NUM);
GPIO_CLEAR_INTERRUPT(GPIO_B_BASE, 0xFF);
@ -115,10 +115,10 @@ gpio_port_b_isr()
void
gpio_port_c_isr()
{
ENERGEST_ON(ENERGEST_TYPE_IRQ);
lpm_exit();
ENERGEST_ON(ENERGEST_TYPE_IRQ);
notify(REG(GPIO_C_BASE | GPIO_MIS), GPIO_C_NUM);
GPIO_CLEAR_INTERRUPT(GPIO_C_BASE, 0xFF);
@ -131,10 +131,10 @@ gpio_port_c_isr()
void
gpio_port_d_isr()
{
ENERGEST_ON(ENERGEST_TYPE_IRQ);
lpm_exit();
ENERGEST_ON(ENERGEST_TYPE_IRQ);
notify(REG(GPIO_D_BASE | GPIO_MIS), GPIO_D_NUM);
GPIO_CLEAR_INTERRUPT(GPIO_D_BASE, 0xFF);