diff options
| author | Craig Hesling <hesling@chromium.org> | 2021-07-15 02:20:41 -0400 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2021-07-16 17:36:18 +0000 |
| commit | 6e4ed0664ef649b0170894cc2ac1a738d3673ce1 (patch) | |
| tree | 5d9a0923b0663b317fb73e3348febd8414c27bf2 /util | |
| parent | b0e93341bc75ff677afa520322fb61eaac98c4f1 (diff) | |
| download | chrome-ec-6e4ed0664ef649b0170894cc2ac1a738d3673ce1.tar.gz | |
flash_fp_mcu: Fix interrupt to unbind race caused by pwr_en
Taking control of the pwr_en line causes the FPMCU to power cycle.
This causes an interrupt to the cros-ec driver. The interrupt handler
then races with the subsequent cros-ec unbind attempt.
This can manifest in multiple ways, but one common way is for the
later binding of spidev to fail, since the interrupt handler
reinitialized the cros-ec driver (due to crrev.com/c/1903814).
The spidev attempt then errors out because there are still resources
associated with the device (the reallocated cros-ec objects).
The need to take control of the power enable line to simply keep FPMCU
power enabled is no longer needed on any device.
* The need for this arose during nocturne development, when the pwr_en
line was associated with the SPI interface in ACPI.
This can be seen in https://crrev.com/c/1084686.
This pwr_en control was then added to flash_fp_mcu in
https://crrev.com/c/1114743.
* The pwr_line was then quickly disassociated with the SPI interface
a few days later in https://crrev.com/c/1155565, but wasn't removed
from flash_fp_mcu.
To this day, the FP pwr_en line is controlled in coreboot manually.
It remains powered on when the Chromebook is powered on, irrespective
of drivers.
BRANCH=none
BUG=b:190744837
TEST=Run the following on nocturne, nami, kohaku, dratini, and
volteer.
scp util/flash_fp_mcu ${DUT_HOSTNAME}:/usr/local/bin/flash_fp_mcu
ssh ${DUT_HOSTNAME} flash_fp_mcu --hello
ssh ${DUT_HOSTNAME} flash_fp_mcu
ssh ${DUT_HOSTNAME} flash_fp_mcu --hello
Signed-off-by: Craig Hesling <hesling@chromium.org>
Change-Id: Icc64f7056e21180efd19b2f650b9fe5804cd2906
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3027129
Tested-by: Patryk Duda <patrykd@google.com>
Reviewed-by: Patryk Duda <patrykd@google.com>
Reviewed-by: Josie Nordrum <josienordrum@google.com>
Diffstat (limited to 'util')
| -rw-r--r-- | util/flash_fp_mcu | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/util/flash_fp_mcu b/util/flash_fp_mcu index 827aa398de..85ab64dfc5 100644 --- a/util/flash_fp_mcu +++ b/util/flash_fp_mcu @@ -299,13 +299,6 @@ flash_fp_mcu_stm32() { echo "Flashing ${transport} device ID: ${deviceid}" - # Ensure the ACPI is not cutting power when unloading cros-ec-spi - if [[ "${gpio_pwren}" -gt 0 ]]; then - gpio export "${gpio_pwren}" - gpio out "${gpio_pwren}" - gpio 1 "${gpio_pwren}" - fi - # Remove cros_fp if present klog "Unbinding cros-ec driver" if [[ "${transport}" == "UART" ]]; then @@ -409,11 +402,6 @@ flash_fp_mcu_stm32() { klog "Binding cros-ec driver" echo "" > "/sys/bus/spi/devices/${deviceid}/driver_override" echo "${deviceid}" > /sys/bus/spi/drivers/cros-ec-spi/bind - - # Kernel driver is back, we are no longer controlling power - if [[ "${gpio_pwren}" -gt 0 ]]; then - gpio unexport "${gpio_pwren}" - fi fi if [[ "${cmd_exit_status}" -ne 0 ]]; then |