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

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

[Andre Eikmeyer]

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

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

[Mika Westerberg]

Hi,

On Wed, Nov 11, 2026 at 02:08:51PM +0100, Andre Eikmeyer wrote:
> 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.

Cool, does it also wake up if you plug something to the TB ports?

> 
> 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

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

[André Eikmeyer]

On Wed, 11 Nov 2026 14:21:12 +0100
Mika Westerberg <mika.westerberg@linux.intel.com> wrote:

> Cool, does it also wake up if you plug something to the TB ports?

Hi Mika,

yup. working perfectly here. There is also a bunch of other patches
for hotplug and such. I even get pkg-c10 on all T2 macbooks.
But that is for another day.

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

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential
issues to consider:
- [High] thunderbolt: root switch skipped in tb_lc_set_wake() and lane
  init on ICL
- [High] thunderbolt: missing DL_FLAG_RPM_ACTIVE in add_link() suspends
  active PCIe
--

commit 7b8fe879e2da1e2a2041c441ee239114a6aec29b
Author: Andre Eikmeyer <dev@deq.rocks>

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

This commit adds tb_switch_is_ice_lake() and enables software connection
manager runtime PM on the Ice Lake host router.

> diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
> index 418ad0a61a5de..139ef49b49e5c 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);

[Severity: High]
Does enabling runtime PM on the Ice Lake root switch put its link
controllers to sleep without configuring wakeups or restarting lane
initialization on resume?

Ice Lake is a generation 3 (non-USB4) router, so tb_switch_suspend() uses
the link controller path: it disables plug events, calls
tb_switch_set_wake() -> tb_lc_set_wake(), and then calls tb_lc_set_sleep()
to set TB_LC_SX_CTRL_SLP on each link controller.  However, tb_lc_set_wake()
bails out on the root switch:

drivers/thunderbolt/lc.c:tb_lc_set_wake() {
	if (sw->generation < 2)
		return 0;

	if (!tb_route(sw))
		return 0;
    ...
}

When a connected device is runtime-suspended, icl_nhi_suspend() keeps force
power on and leaves the root switch in link controller sleep with no wake
bits (WOC, WOD, WOU4, WOP, WODPC, WODPD) programmed.  On runtime resume,
tb_runtime_resume() -> tb_switch_resume() -> tb_port_resume() ->
tb_lc_start_lane_initialization() also returns early on !tb_route(sw)
instead of asserting TB_LC_SX_CTRL_SLI on disconnected downstream lane
adapters.

[Severity: High]
Can enabling runtime PM on Ice Lake allow nhi->dev and the root switch to
runtime-suspend while a tunneled PCIe root port is still active?

On Apple Ice Lake systems, nhi_select_cm() creates the runtime PM device
links to the tunneled PCIe root ports through icl_nhi_add_links() ->
add_link() rather than tb_acpi_add_links():

drivers/thunderbolt/pci.c:add_link() {
	link = device_link_add(&pdev->dev, nhi->dev,
			       DL_FLAG_AUTOREMOVE_SUPPLIER |
			       DL_FLAG_PM_RUNTIME);
    ...
}

Unlike tb_acpi_add_link(), which was updated in f3380cac0c0b ("thunderbolt:
Runtime PM activate both ends of the device link") to wrap device_link_add()
with pm_runtime_get_sync(&pdev->dev), DL_FLAG_RPM_ACTIVE, and
pm_runtime_put(&pdev->dev), add_link() does not pass DL_FLAG_RPM_ACTIVE.
When a PCIe tunnel is already up at boot and the consumer PCIe root port is
already runtime-active when add_link() runs, nhi->dev's runtime PM usage
count is not incremented, allowing the Thunderbolt domain and root switch to
autosuspend underneath the active PCIe tunnel.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261111130851.62101-1-dev@deq.rocks?part=1