[PATCH 3/7] HID: usbhid: do not rely on hid->open when deciding to do IO

From: Dmitry Torokhov
Date: Wed May 31 2017 - 17:00:06 EST


Instead of checking hid->open (that we plan on having HID core manage) in
hid_start_in(), let's allocate a couple of new flags: HID_IN_POLLING and
HID_OPENED, and use them to decide whether we should be submitting URBs or
not.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/hid/usbhid/hid-core.c | 25 ++++++++++++++++++-------
drivers/hid/usbhid/usbhid.h | 11 +++++++++++
2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 62b660622265..d927fe4ba592 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -85,10 +85,10 @@ static int hid_start_in(struct hid_device *hid)
struct usbhid_device *usbhid = hid->driver_data;

spin_lock_irqsave(&usbhid->lock, flags);
- if ((hid->open > 0 || hid->quirks & HID_QUIRK_ALWAYS_POLL) &&
- !test_bit(HID_DISCONNECTED, &usbhid->iofl) &&
- !test_bit(HID_SUSPENDED, &usbhid->iofl) &&
- !test_and_set_bit(HID_IN_RUNNING, &usbhid->iofl)) {
+ if (test_bit(HID_IN_POLLING, &usbhid->iofl) &&
+ !test_bit(HID_DISCONNECTED, &usbhid->iofl) &&
+ !test_bit(HID_SUSPENDED, &usbhid->iofl) &&
+ !test_and_set_bit(HID_IN_RUNNING, &usbhid->iofl)) {
rc = usb_submit_urb(usbhid->urbin, GFP_ATOMIC);
if (rc != 0) {
clear_bit(HID_IN_RUNNING, &usbhid->iofl);
@@ -272,13 +272,13 @@ static int usbhid_restart_ctrl_queue(struct usbhid_device *usbhid)
static void hid_irq_in(struct urb *urb)
{
struct hid_device *hid = urb->context;
- struct usbhid_device *usbhid = hid->driver_data;
+ struct usbhid_device *usbhid = hid->driver_data;
int status;

switch (urb->status) {
case 0: /* success */
usbhid->retry_delay = 0;
- if ((hid->quirks & HID_QUIRK_ALWAYS_POLL) && !hid->open)
+ if (!test_bit(HID_OPENED, &usbhid->iofl))
break;
usbhid_mark_busy(usbhid);
if (!test_bit(HID_RESUME_RUNNING, &usbhid->iofl)) {
@@ -692,6 +692,8 @@ static int usbhid_open(struct hid_device *hid)
goto done;
}
usbhid->intf->needs_remote_wakeup = 1;
+ set_bit(HID_OPENED, &usbhid->iofl);
+ set_bit(HID_IN_POLLING, &usbhid->iofl);
set_bit(HID_RESUME_RUNNING, &usbhid->iofl);
res = hid_start_in(hid);
if (res) {
@@ -701,6 +703,9 @@ static int usbhid_open(struct hid_device *hid)
} else {
/* no use opening if resources are insufficient */
hid->open--;
+ clear_bit(HID_OPENED, &usbhid->iofl);
+ if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL))
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
res = -EBUSY;
usbhid->intf->needs_remote_wakeup = 0;
}
@@ -734,6 +739,9 @@ static void usbhid_close(struct hid_device *hid)
*/
spin_lock_irq(&usbhid->lock);
if (!--hid->open) {
+ if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL))
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
+ clear_bit(HID_OPENED, &usbhid->iofl);
spin_unlock_irq(&usbhid->lock);
hid_cancel_delayed_stuff(usbhid);
if (!(hid->quirks & HID_QUIRK_ALWAYS_POLL)) {
@@ -1135,6 +1143,7 @@ static int usbhid_start(struct hid_device *hid)
ret = usb_autopm_get_interface(usbhid->intf);
if (ret)
goto fail;
+ set_bit(HID_IN_POLLING, &usbhid->iofl);
usbhid->intf->needs_remote_wakeup = 1;
ret = hid_start_in(hid);
if (ret) {
@@ -1176,8 +1185,10 @@ static void usbhid_stop(struct hid_device *hid)
if (WARN_ON(!usbhid))
return;

- if (hid->quirks & HID_QUIRK_ALWAYS_POLL)
+ if (hid->quirks & HID_QUIRK_ALWAYS_POLL) {
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
usbhid->intf->needs_remote_wakeup = 0;
+ }

clear_bit(HID_STARTED, &usbhid->iofl);
spin_lock_irq(&usbhid->lock); /* Sync with error and led handlers */
diff --git a/drivers/hid/usbhid/usbhid.h b/drivers/hid/usbhid/usbhid.h
index ffcd329b3c3b..da9c61d54be6 100644
--- a/drivers/hid/usbhid/usbhid.h
+++ b/drivers/hid/usbhid/usbhid.h
@@ -49,6 +49,17 @@ struct usb_interface *usbhid_find_interface(int minor);
#define HID_KEYS_PRESSED 10
#define HID_NO_BANDWIDTH 11
#define HID_RESUME_RUNNING 12
+/*
+ * The device is opened, meaning there is a client that is interested
+ * in data coming from the device.
+ */
+#define HID_OPENED 13
+/*
+ * We are polling input endpoint by [re]submitting IN URB, because
+ * either HID device is opened or ALWAYS POLL quirk is set for the
+ * device.
+ */
+#define HID_IN_POLLING 14

/*
* USB-specific HID struct, to be pointed to
--
2.13.0.506.g27d5fe0cd-goog