Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1661744

[PATCH 2/3] HID: usbhid: enable autosuspend for devices whose ...

Show all headers | View raw

From: Yueyao Zhu <yueyao@google.com>

usage pages only points to CONSUMER. This allows autosuspend
to be enabled and thus power saved on CONSUMER hid devices.
Yet hid devices use other usage pages are not affected, e.g.
keyboard, mouse.

Signed-off-by: Yueyao Zhu <yueyao@google.com>
---
 drivers/hid/usbhid/hid-core.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 83772fa7d92a..f2696b4098b5 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -1270,6 +1270,31 @@ static struct hid_ll_driver usb_hid_driver = {
 	.idle = usbhid_idle,
 };
 
+static bool usbhid_usage_is_consumer(struct hid_device *hid)
+{
+	int i;
+	struct hid_report_enum *input_report_enum =
+			hid->report_enum + HID_INPUT_REPORT;
+	struct list_head *report_list = &input_report_enum->report_list;
+	struct hid_report *report;
+	unsigned int usage_page;
+
+	if (list_empty(report_list))
+		return false;
+
+	list_for_each_entry(report, report_list, list) {
+		for (i = 0; i < report->maxfield; i++) {
+			/* only checks Application field */
+			usage_page =
+				report->field[i]->application & HID_USAGE_PAGE;
+			if (usage_page != HID_UP_CONSUMER)
+				return false;
+		}
+	}
+
+	return true;
+}
+
 static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct usb_host_interface *interface = intf->cur_altsetting;
@@ -1363,6 +1388,18 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
 		goto err_free;
 	}
 
+	/*
+	 * Autosuspend interfaces which have only consumer usage page inputs.
+	 * This allows autosuspending devices which adhere to the Android USB
+	 * headset spec while not autosuspending general keyboards, mice, and
+	 * joysticks which may misbehave.
+	 */
+	if (usbhid_usage_is_consumer(hid)) {
+		intf->needs_remote_wakeup = true;
+		usb_allow_interface_autosuspend(intf);
+		hid_info(hid, "autosuspend enabled on the hid interface\n");
+	}
+
 	return 0;
 err_free:
 	kfree(usbhid);
-- 
2.13.0.506.g27d5fe0cd-goog

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 0/3] USB: add API for interface driver to vote for autosuspend Yueyao Zhu <yueyao.zhu@gmail.com> - 2017-06-09 00:00 +0200
  [PATCH 3/3] sound: usb: allow interfaces that the driver claims to autosuspend Yueyao Zhu <yueyao.zhu@gmail.com> - 2017-06-09 00:00 +0200
  [PATCH 2/3] HID: usbhid: enable autosuspend for devices whose ... Yueyao Zhu <yueyao.zhu@gmail.com> - 2017-06-09 00:10 +0200
  Re: [PATCH 0/3] USB: add API for interface driver to vote for  autosuspend Alan Stern <stern@rowland.harvard.edu> - 2017-06-09 17:00 +0200

csiph-web