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path: root/drivers/thunderbolt/acpi.c
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Diffstat (limited to 'drivers/thunderbolt/acpi.c')
-rw-r--r--drivers/thunderbolt/acpi.c68
1 files changed, 25 insertions, 43 deletions
diff --git a/drivers/thunderbolt/acpi.c b/drivers/thunderbolt/acpi.c
index c9b6bb46111c..45d1415871b4 100644
--- a/drivers/thunderbolt/acpi.c
+++ b/drivers/thunderbolt/acpi.c
@@ -32,40 +32,20 @@ static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
goto out_put;
/*
- * Try to find physical device walking upwards to the hierarcy.
- * We need to do this because the xHCI driver might not yet be
- * bound so the USB3 SuperSpeed ports are not yet created.
+ * Ignore USB3 ports here as USB core will set up device links between
+ * tunneled USB3 devices and NHI host during USB device creation.
+ * USB3 ports might not even have a physical device yet if xHCI driver
+ * isn't bound yet.
*/
- do {
- dev = acpi_get_first_physical_node(adev);
- if (dev)
- break;
-
- adev = acpi_dev_parent(adev);
- } while (adev);
-
- /*
- * Check that the device is PCIe. This is because USB3
- * SuperSpeed ports have this property and they are not power
- * managed with the xHCI and the SuperSpeed hub so we create the
- * link from xHCI instead.
- */
- while (dev && !dev_is_pci(dev))
- dev = dev->parent;
-
- if (!dev)
+ dev = acpi_get_first_physical_node(adev);
+ if (!dev || !dev_is_pci(dev))
goto out_put;
- /*
- * Check that this actually matches the type of device we
- * expect. It should either be xHCI or PCIe root/downstream
- * port.
- */
+ /* Check that this matches a PCIe root/downstream port. */
pdev = to_pci_dev(dev);
- if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI ||
- (pci_is_pcie(pdev) &&
- (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
- pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) {
+ if (pci_is_pcie(pdev) &&
+ (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
+ pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM)) {
const struct device_link *link;
/*
@@ -106,7 +86,7 @@ out_put:
* @nhi ACPI node. For each reference a device link is added. The link
* is automatically removed by the driver core.
*
- * Returns %true if at least one link was created.
+ * Returns %true if at least one link was created, %false otherwise.
*/
bool tb_acpi_add_links(struct tb_nhi *nhi)
{
@@ -133,8 +113,10 @@ bool tb_acpi_add_links(struct tb_nhi *nhi)
/**
* tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
*
- * Returns %true if the platform granted OS native control over
- * TBT/USB4. In this case software based connection manager can be used,
+ * Return: %true if the platform granted OS native control over
+ * TBT/USB4, %false otherwise.
+ *
+ * When returned %true, software based connection manager can be used,
* otherwise there is firmware based connection manager running.
*/
bool tb_acpi_is_native(void)
@@ -146,8 +128,8 @@ bool tb_acpi_is_native(void)
/**
* tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
*
- * When software based connection manager is used, this function
- * returns %true if platform allows native USB3 tunneling.
+ * Return: %true if software based connection manager is used and
+ * platform allows native USB 3.x tunneling, %false otherwise.
*/
bool tb_acpi_may_tunnel_usb3(void)
{
@@ -159,8 +141,8 @@ bool tb_acpi_may_tunnel_usb3(void)
/**
* tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
*
- * When software based connection manager is used, this function
- * returns %true if platform allows native DP tunneling.
+ * Return: %true if software based connection manager is used and
+ * platform allows native DP tunneling, %false otherwise.
*/
bool tb_acpi_may_tunnel_dp(void)
{
@@ -172,8 +154,8 @@ bool tb_acpi_may_tunnel_dp(void)
/**
* tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
*
- * When software based connection manager is used, this function
- * returns %true if platform allows native PCIe tunneling.
+ * Return: %true if software based connection manager is used and
+ * platform allows native PCIe tunneling, %false otherwise.
*/
bool tb_acpi_may_tunnel_pcie(void)
{
@@ -185,8 +167,8 @@ bool tb_acpi_may_tunnel_pcie(void)
/**
* tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
*
- * When software based connection manager is used, this function
- * returns %true if platform allows XDomain connections.
+ * Return: %true if software based connection manager is used and
+ * platform allows XDomain tunneling, %false otherwise.
*/
bool tb_acpi_is_xdomain_allowed(void)
{
@@ -276,7 +258,7 @@ static int tb_acpi_retimer_set_power(struct tb_port *port, bool power)
*
* This should only be called if the USB4/TBT link is not up.
*
- * Returns %0 on success.
+ * Return: %0 on success, negative errno otherwise.
*/
int tb_acpi_power_on_retimers(struct tb_port *port)
{
@@ -290,7 +272,7 @@ int tb_acpi_power_on_retimers(struct tb_port *port)
* This is the opposite of tb_acpi_power_on_retimers(). After returning
* successfully the normal operations with the @port can continue.
*
- * Returns %0 on success.
+ * Return: %0 on success, negative errno otherwise.
*/
int tb_acpi_power_off_retimers(struct tb_port *port)
{