[PATCH] thunderbolt: Enable runtime PM for the Ice Lake router with the software CM

[Andre Eikmeyer <dev@deq.rocks>]

The firmware connection manager reports RTD3 for the Ice Lake router.
On Apple systems the software connection manager takes over and enables
runtime PM only for USB4 routers, so the Ice Lake NHI stays in D0 for as
long as the driver is bound and the package does not reach deep C-states.

Enable runtime PM for the Ice Lake router as well. The Ice Lake NHI
already has runtime suspend and resume callbacks.

Tested on a MacBookAir9,1.

Signed-off-by: Andre Eikmeyer <dev@deq.rocks>
---
 drivers/thunderbolt/tb.c |  5 +++--
 drivers/thunderbolt/tb.h | 12 ++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 418ad0a61a..139ef49b49 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -3044,8 +3044,9 @@ static int tb_start(struct tb *tb, bool reset)
 	 * implement the necessary router operations.
 	 */
 	tb->root_switch->no_nvm_upgrade = !tb_switch_is_usb4(tb->root_switch);
-	/* All USB4 routers support runtime PM */
-	tb->root_switch->rpm = tb_switch_is_usb4(tb->root_switch);
+	/* All USB4 routers support runtime PM. Ice Lake also supports RTD3 */
+	tb->root_switch->rpm = tb_switch_is_usb4(tb->root_switch) ||
+			       tb_switch_is_ice_lake(tb->root_switch);
 
 	ret = tb_switch_configure(tb->root_switch);
 	if (ret) {
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index e86845762e..eff4a342d6 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1011,6 +1011,18 @@ static inline bool tb_switch_is_tiger_lake(const struct tb_switch *sw)
 	return false;
 }
 
+static inline bool tb_switch_is_ice_lake(const struct tb_switch *sw)
+{
+	if (sw->config.vendor_id == PCI_VENDOR_ID_INTEL) {
+		switch (sw->config.device_id) {
+		case PCI_DEVICE_ID_INTEL_ICL_NHI0:
+		case PCI_DEVICE_ID_INTEL_ICL_NHI1:
+			return true;
+		}
+	}
+	return false;
+}
+
 /**
  * tb_switch_is_icm() - Is the switch handled by ICM firmware
  * @sw: Switch to check

base-commit: 13527afe5f15c60b82920fe9915f3cabf1315302