cpu/stm32f1: CPU hangs after wake-up from STOP power mode #13918
Description
Description
I am experiencing odd behavior with the STM32F103C8 CPU on current master. I am running the application tests/periph_pm on the board bluepill. After the RTC woke up the board from STM32_PM_STOP, it hangs.
After digging around I found out that the problem is solved by introducing two NOPs before re-initializing the clocks:
diff --git a/cpu/stm32_common/periph/pm.c b/cpu/stm32_common/periph/pm.c
index 4b4875ebf..b51b9d817 100644
--- a/cpu/stm32_common/periph/pm.c
+++ b/cpu/stm32_common/periph/pm.c
@@ -135,6 +136,8 @@ void pm_set(unsigned mode)
if (deep) {
/* Re-init clock after STOP */
+ __asm__("nop\n\t");
+ __asm__("nop\n\t");
stmclk_init_sysclk();
}
}Steps to reproduce the issue
Flash tests/periph_pm on the board bluepill:
Expected results
(The first unblock is required to release the block issued by the UART behind stdio_uart.)
cd tests/periph_pm
make BOARD=bluepill flash term
unblock 1
2020-04-21 18:44:05,125 # unblock 1
2020-04-21 18:44:05,126 # Unblocking power mode 1.
unblock_rtc 1 2
2020-04-21 18:44:07,139 # unblock_rtc 1 2
2020-04-21 18:44:07,140 # Unblocking power mode 1 for 2 seconds.
(... wait at least 2 secs)
help
2020-04-21 18:44:10,816 # help
2020-04-21 18:44:10,817 # Command Description
2020-04-21 18:44:10,817 # ---------------------------------------
2020-04-21 18:44:10,818 # off turn off
2020-04-21 18:44:10,818 # reboot reboot
2020-04-21 18:44:10,819 # block block power mode
2020-04-21 18:44:10,820 # set set power mode
2020-04-21 18:44:10,821 # unblock unblock power mode
2020-04-21 18:44:10,822 # unblock_rtc temporary unblock power mode
Actual results
cd tests/periph_pm
make BOARD=bluepill flash term
unblock 1
2020-04-21 18:44:05,125 # unblock 1
2020-04-21 18:44:05,126 # Unblocking power mode 1.
unblock_rtc 1 2
2020-04-21 18:44:07,139 # unblock_rtc 1 2
2020-04-21 18:44:07,140 # Unblocking power mode 1 for 2 seconds.
(... wait at least 2 secs)
help
(... the system is dead)
Versions
Operating System Environment
----------------------------
Operating System: "Manjaro Linux"
Kernel: Linux 5.4.33-3-MANJARO x86_64 unknown
System shell: GNU bash, version 5.0.16(1)-release (x86_64-pc-linux-gnu)
make's shell: GNU bash, version 5.0.16(1)-release (x86_64-pc-linux-gnu)
Installed compiler toolchains
-----------------------------
native gcc: gcc (Arch Linux 9.3.0-1) 9.3.0
arm-none-eabi-gcc: arm-none-eabi-gcc (Arch Repository) 9.3.0
avr-gcc: missing
mips-mti-elf-gcc: missing
msp430-gcc: missing
riscv-none-embed-gcc: missing
xtensa-esp32-elf-gcc: missing
xtensa-esp8266-elf-gcc: missing
clang: clang version 9.0.1
Installed compiler libs
-----------------------
arm-none-eabi-newlib: "3.3.0"
mips-mti-elf-newlib: missing
riscv-none-embed-newlib: missing
xtensa-esp32-elf-newlib: missing
xtensa-esp8266-elf-newlib: missing
avr-libc: missing (missing)
Installed development tools
---------------------------
ccache: missing
cmake: cmake version 3.17.1
cppcheck: missing
doxygen: 1.8.17
git: git version 2.26.1
make: GNU Make 4.3
openocd: Open On-Chip Debugger 0.10.0
python: Python 3.8.2
python2: Python 2.7.17
python3: Python 3.8.2
flake8: error: /usr/bin/python3: No module named flake8
coccinelle: missing