[PATCH RFC 2/2] usb: typec: ucsi: increase timeout for PPM reset operations

Fedor Pchelkin
2025-02-06T18:44:01Z

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>
---
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
--
2.48.1