[PATCH 1/2] usb: Prefer firmware values when determining whether a port is removable

From: Matthew Garrett
Date: Wed Apr 08 2015 - 19:36:25 EST


Windows appears to pay more attention to the ACPI values than any hub
configuration, so prefer the firmware's opinion on whether a port is
fixed or removable before falling back to the hub values.

Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
---
drivers/usb/core/hub.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d7c3d5a..ac33fdd 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2350,6 +2350,23 @@ static void set_usb_port_removable(struct usb_device *udev)

hub = usb_hub_to_struct_hub(udev->parent);

+ /*
+ * If the platform firmware has provided information about a port,
+ * use that to determine whether it's removable.
+ */
+ switch (hub->ports[udev->portnum - 1]->connect_type) {
+ case USB_PORT_CONNECT_TYPE_HOT_PLUG:
+ udev->removable = USB_DEVICE_REMOVABLE;
+ return;
+ case USB_PORT_CONNECT_TYPE_HARD_WIRED:
+ udev->removable = USB_DEVICE_FIXED;
+ return;
+ }
+
+ /*
+ * Otherwise, check whether the hub knows whether a port is removable
+ * or not
+ */
wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);

if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
@@ -2369,21 +2386,6 @@ static void set_usb_port_removable(struct usb_device *udev)
else
udev->removable = USB_DEVICE_FIXED;

- /*
- * Platform firmware may have populated an alternative value for
- * removable. If the parent port has a known connect_type use
- * that instead.
- */
- switch (hub->ports[udev->portnum - 1]->connect_type) {
- case USB_PORT_CONNECT_TYPE_HOT_PLUG:
- udev->removable = USB_DEVICE_REMOVABLE;
- break;
- case USB_PORT_CONNECT_TYPE_HARD_WIRED:
- udev->removable = USB_DEVICE_FIXED;
- break;
- default: /* use what was set above */
- break;
- }
}

/**
--
2.3.4

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