It is observed that on some systems an initial PPM reset during the boot phase can trigger a timeout:

[ 6.482546] ucsi_acpi USBC000:00: failed to reset PPM! [ 6.482551] ucsi_acpi USBC000:00: error -ETIMEDOUT: PPM init failed

Still, increasing the timeout value, albeit being the most straightforward solution, eliminates the problem: the initial PPM reset may take up to ~8000-10000ms on some Lenovo laptops. When it is reset after the above period of time (or even if ucsi_reset_ppm() is not called overall), UCSI works as expected.

Moreover, if the ucsi_acpi module is loaded/unloaded manually after the system has booted, reading the CCI values and resetting the PPM works perfectly, without any timeout. Thus it's only a boot-time issue.

The reason for this behavior is not clear but it may be the consequence of some tricks that the firmware performs or be an actual firmware bug. As a workaround, increase the timeout to avoid failing the UCSI initialization prematurely.

Fixes: b1b59e16075f ("usb: typec: ucsi: Increase command completion timeout value") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin boddah8794@gmail.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com --- Add Heikki's Reviewed-by tag.

drivers/usb/typec/ucsi/ucsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 0fe1476f4c29..7a56d3f840d7 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -25,7 +25,7 @@ * difficult to estimate the time it takes for the system to process the command * before it is actually passed to the PPM. */ -#define UCSI_TIMEOUT_MS 5000 +#define UCSI_TIMEOUT_MS 10000

/* * UCSI_SWAP_TIMEOUT_MS - Timeout for role swap requests