On some OEM systems, adding a W7900 dGPU triggers RAS errors and hangs at a black screen on startup. This issue occurs only if `ucsi_acpi` has loaded before `amdgpu` has loaded. The reason for this failure is that `amdgpu` uses power_supply_is_system_supplied() to determine if running on AC or DC power at startup. If this value is reported incorrectly the dGPU will also be programmed incorrectly and trigger errors. power_supply_is_system_supplied() reports the wrong value because UCSI power supplies provided as part of the system don't properly report the scope as "DEVICE" scope (not powering the system). In order to fix this issue check the capabilities reported from the UCSI power supply to ensure that it supports charging a battery and that it can be powered by AC. Mark the scope accordingly. Cc: stable@xxxxxxxxxxxxxxx Fixes: a7fbfd44c020 ("usb: typec: ucsi: Mark dGPUs as DEVICE scope") Link: https://www.intel.com/content/www/us/en/products/docs/io/universal-serial-bus/usb-type-c-ucsi-spec.html p28 Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> --- Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Cc: Alex Deucher <Alexander.Deucher@xxxxxxx>> Cc: Richard Gong <Richard.Gong@xxxxxxx> v2->v3: * Pick up tag * Add missing stable tag * Drop patch 2, we'll just avoid upstreaming it. --- drivers/usb/typec/ucsi/psy.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c index 384b42267f1f..b35c6e07911e 100644 --- a/drivers/usb/typec/ucsi/psy.c +++ b/drivers/usb/typec/ucsi/psy.c @@ -37,6 +37,15 @@ static int ucsi_psy_get_scope(struct ucsi_connector *con, struct device *dev = con->ucsi->dev; device_property_read_u8(dev, "scope", &scope); + if (scope == POWER_SUPPLY_SCOPE_UNKNOWN) { + u32 mask = UCSI_CAP_ATTR_POWER_AC_SUPPLY | + UCSI_CAP_ATTR_BATTERY_CHARGING; + + if (con->ucsi->cap.attributes & mask) + scope = POWER_SUPPLY_SCOPE_SYSTEM; + else + scope = POWER_SUPPLY_SCOPE_DEVICE; + } val->intval = scope; return 0; } -- 2.34.1