@@ -632,6 +632,8 @@ static const struct dev_pm_ops nhi_pm_ops = {
* pci-tunnels stay alive.
*/
.restore_noirq = nhi_resume_noirq,
+ .runtime_suspend = nhi_suspend_noirq,
+ .runtime_resume = nhi_resume_noirq,
};
static struct pci_device_id nhi_ids[] = {
@@ -323,6 +323,12 @@ void thunderbolt_power_init(struct tb *tb)
tb->power = power;
+ pm_runtime_allow(nhi_dev);
+ pm_runtime_set_autosuspend_delay(nhi_dev, 10000);
+ pm_runtime_use_autosuspend(nhi_dev);
+ pm_runtime_mark_last_busy(nhi_dev);
+ pm_runtime_put_autosuspend(nhi_dev);
+
return;
err_free:
@@ -339,6 +345,9 @@ void thunderbolt_power_fini(struct tb *tb)
if (!power)
return; /* thunderbolt_power_init() failed */
+ pm_runtime_get(nhi_dev);
+ pm_runtime_forbid(nhi_dev);
+
tb->power = NULL;
dev_pm_domain_set(upstream_dev, NULL);
@@ -5,6 +5,7 @@
*/
#include <linux/delay.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include "tb.h"
@@ -326,6 +327,11 @@ void tb_switch_free(struct tb_switch *sw)
if (!sw->is_unplugged)
tb_plug_events_active(sw, false);
+ if (sw != sw->tb->root_switch) {
+ pm_runtime_mark_last_busy(&sw->tb->nhi->pdev->dev);
+ pm_runtime_put_autosuspend(&sw->tb->nhi->pdev->dev);
+ }
+
kfree(sw->ports);
kfree(sw->drom);
kfree(sw);
@@ -420,6 +426,9 @@ struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
if (tb_plug_events_active(sw, true))
goto err;
+ if (tb->root_switch)
+ pm_runtime_get(&tb->nhi->pdev->dev);
+
return sw;
err:
kfree(sw->ports);
@@ -7,6 +7,7 @@
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>
+#include <linux/pm_runtime.h>
#include "tb.h"
#include "tb_regs.h"
@@ -217,8 +218,11 @@ static void tb_handle_hotplug(struct work_struct *work)
{
struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
struct tb *tb = ev->tb;
+ struct device *dev = &tb->nhi->pdev->dev;
struct tb_switch *sw;
struct tb_port *port;
+
+ pm_runtime_get(dev);
mutex_lock(&tb->lock);
if (!tb->hotplug_active)
goto out; /* during init, suspend or shutdown */
@@ -274,6 +278,8 @@ static void tb_handle_hotplug(struct work_struct *work)
out:
mutex_unlock(&tb->lock);
kfree(ev);
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
}
/**
@@ -433,4 +439,11 @@ void thunderbolt_resume(struct tb *tb)
tb->hotplug_active = true;
mutex_unlock(&tb->lock);
tb_info(tb, "resume finished\n");
+
+ /*
+ * If runtime resuming due to a hotplug event (rather than resuming
+ * from system sleep), wait for it to arrive. May take about 700 ms.
+ */
+ if (tb->nhi->pdev->dev.power.runtime_status == RPM_RESUMING)
+ msleep(1000);
}
Runtime suspend the NHI when no Thunderbolt devices have been plugged in for 10 sec (user-configurable via autosuspend_delay_ms in sysfs). The NHI is not able to detect plug events while suspended, it relies on the GPE handler to resume it on hotplug. After the NHI resumes, it takes about 700 ms until a hotplug event appears on the RX ring. In case autosuspend_delay_ms has been reduced to 0 by the user, we need to wait in tb_resume() to avoid going back to sleep before we had a chance to detect a hotplugged device. A runtime pm ref is held for the duration of tb_handle_hotplug() to keep the NHI awake while the hotplug event is processed. Apart from that we acquire a runtime pm ref for each newly allocated switch (except for the root switch) and drop one when a switch is freed, thereby ensuring the NHI stays active as long as devices are plugged in. This behaviour is identical to the macOS driver. Just as the rest of the Thunderbolt driver, runtime PM is an ongoing work in progress. In particular, two issues remain: * When a daisy-chained device is hotplugged and a PCIe port between the end of the chain and the host controller is in D3hot, the pciehp hotplug interrupt cannot be expected to be delivered. The plug event sent via the CIO switch to the NHI serves as a side-band signal and the NHI should runtime resume the PCIe hotplug port on which the plug event occurred. We do not support daisy chaining yet so this is only an issue for PCI tunnels established by the EFI driver. * On Cactus Ridge and newer, directly-attached DisplayPort devices are not wired to the GPU, but rather the DP signal is routed through the Thunderbolt controller. It may thus be necessary to check presence of attached DisplayPort devices when scanning the root switch and acquire a runtime ref for each of them to prevent the controller from powering off while displays are attached. Unfortunately my own machine predates Cactus Ridge and wires the DP signal directly to the GPU, so I cannot test this. Cc: Andreas Noever <andreas.noever@gmail.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> --- drivers/thunderbolt/nhi.c | 2 ++ drivers/thunderbolt/power.c | 9 +++++++++ drivers/thunderbolt/switch.c | 9 +++++++++ drivers/thunderbolt/tb.c | 13 +++++++++++++ 4 files changed, 33 insertions(+)