Previously, reset over USB CDC was done by calling esp_restart from
an interrupt handler. This works only until some restart hook function
is registered using esp_register_shutdown_handler, and the hook
function tries to do something that isn’t allowed in an interrupt
handler. One such case is with Wi-Fi. When Wi-Fi driver is installed,
it registers esp_wifi_stop as a shutdown handler function. However
esp_wifi_stop cannot be called from an ISR, and hence we shouldn’t
call esp_restart from an ISR either.
This commit modifies USB CDC driver to call esp_restart by posting it
to esp_timer task.
Closes https://github.com/espressif/esp-idf/issues/7404
By unchecking "Place panic handler code in IRAM" in the menuconfig,
the panic handlers will be placed in flash. Of course, flash cache must
be activated when entering panic handlers.
