From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH v2 6/8] HID: usbhid: remove custom locking from usbhid_open/close
Date: Tue, 6 Jun 2017 23:59:36 -0700 [thread overview]
Message-ID: <20170607065938.33332-7-dmitry.torokhov@gmail.com> (raw)
In-Reply-To: <20170607065938.33332-1-dmitry.torokhov@gmail.com>
Now that HID core enforces serialization of transport driver open/close
calls we can remove custom locking from usbhid driver.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/hid/usbhid/hid-core.c | 115 +++++++++++++++++++-----------------------
1 file changed, 53 insertions(+), 62 deletions(-)
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index d927fe4ba592..76013eb5cb7f 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -70,8 +70,6 @@ MODULE_PARM_DESC(quirks, "Add/modify USB HID quirks by specifying "
/*
* Input submission and I/O error handler.
*/
-static DEFINE_MUTEX(hid_open_mut);
-
static void hid_io_error(struct hid_device *hid);
static int hid_submit_out(struct hid_device *hid);
static int hid_submit_ctrl(struct hid_device *hid);
@@ -680,50 +678,48 @@ static int hid_get_class_descriptor(struct usb_device *dev, int ifnum,
static int usbhid_open(struct hid_device *hid)
{
struct usbhid_device *usbhid = hid->driver_data;
- int res = 0;
-
- mutex_lock(&hid_open_mut);
- if (!hid->open++) {
- res = usb_autopm_get_interface(usbhid->intf);
- /* the device must be awake to reliably request remote wakeup */
- if (res < 0) {
- hid->open--;
- res = -EIO;
- 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) {
- if (res != -ENOSPC) {
- hid_io_error(hid);
- res = 0;
- } 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;
- }
- }
- usb_autopm_put_interface(usbhid->intf);
+ int res;
- /*
- * In case events are generated while nobody was listening,
- * some are released when the device is re-opened.
- * Wait 50 msec for the queue to empty before allowing events
- * to go through hid.
- */
- if (res == 0 && !(hid->quirks & HID_QUIRK_ALWAYS_POLL))
- msleep(50);
- clear_bit(HID_RESUME_RUNNING, &usbhid->iofl);
+ if (hid->quirks & HID_QUIRK_ALWAYS_POLL)
+ return 0;
+
+ res = usb_autopm_get_interface(usbhid->intf);
+ /* the device must be awake to reliably request remote wakeup */
+ if (res < 0)
+ return -EIO;
+
+ usbhid->intf->needs_remote_wakeup = 1;
+
+ set_bit(HID_RESUME_RUNNING, &usbhid->iofl);
+ set_bit(HID_OPENED, &usbhid->iofl);
+ set_bit(HID_IN_POLLING, &usbhid->iofl);
+
+ res = hid_start_in(hid);
+ if (res) {
+ if (res != -ENOSPC) {
+ hid_io_error(hid);
+ res = 0;
+ } else {
+ /* no use opening if resources are insufficient */
+ res = -EBUSY;
+ clear_bit(HID_OPENED, &usbhid->iofl);
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
+ usbhid->intf->needs_remote_wakeup = 0;
+ }
}
-done:
- mutex_unlock(&hid_open_mut);
+
+ usb_autopm_put_interface(usbhid->intf);
+
+ /*
+ * In case events are generated while nobody was listening,
+ * some are released when the device is re-opened.
+ * Wait 50 msec for the queue to empty before allowing events
+ * to go through hid.
+ */
+ if (res == 0)
+ msleep(50);
+
+ clear_bit(HID_RESUME_RUNNING, &usbhid->iofl);
return res;
}
@@ -731,27 +727,22 @@ static void usbhid_close(struct hid_device *hid)
{
struct usbhid_device *usbhid = hid->driver_data;
- mutex_lock(&hid_open_mut);
+ if (hid->quirks & HID_QUIRK_ALWAYS_POLL)
+ return;
- /* protecting hid->open to make sure we don't restart
- * data acquistion due to a resumption we no longer
- * care about
+ /*
+ * Make sure we don't restart data acquisition due to
+ * a resumption we no longer care about by avoiding racing
+ * with hid_start_in().
*/
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)) {
- usb_kill_urb(usbhid->urbin);
- usbhid->intf->needs_remote_wakeup = 0;
- }
- } else {
- spin_unlock_irq(&usbhid->lock);
- }
- mutex_unlock(&hid_open_mut);
+ clear_bit(HID_IN_POLLING, &usbhid->iofl);
+ clear_bit(HID_OPENED, &usbhid->iofl);
+ spin_unlock_irq(&usbhid->lock);
+
+ hid_cancel_delayed_stuff(usbhid);
+ usb_kill_urb(usbhid->urbin);
+ usbhid->intf->needs_remote_wakeup = 0;
}
/*
--
2.13.0.506.g27d5fe0cd-goog
next prev parent reply other threads:[~2017-06-07 7:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-07 6:59 [PATCH v2 0/8] HID: Consolidate serializing ope/close in transport drivers Dmitry Torokhov
2017-06-07 6:59 ` [PATCH v2 1/8] HID: hiddev: use hid_hw_open/close instead of usbhid_open/close Dmitry Torokhov
2017-06-07 6:59 ` [PATCH v2 2/8] HID: hiddev: use hid_hw_power instead of usbhid_get/put_power Dmitry Torokhov
2017-06-07 8:40 ` Andy Shevchenko
2017-06-07 6:59 ` [PATCH v2 3/8] HID: usbhid: do not rely on hid->open when deciding to do IO Dmitry Torokhov
2017-06-07 6:59 ` [PATCH v2 4/8] HID: serialize hid_hw_open and hid_hw_close Dmitry Torokhov
2017-06-07 6:59 ` [PATCH v2 5/8] HID: i2c-hid: remove custom locking from i2c_hid_open/close Dmitry Torokhov
2017-06-07 6:59 ` Dmitry Torokhov [this message]
2017-06-07 6:59 ` [PATCH v2 7/8] greybus: hid: remove custom locking from gb_hid_open/close Dmitry Torokhov
2017-06-07 7:56 ` Greg Kroah-Hartman
2017-06-07 10:02 ` Viresh Kumar
2017-06-07 6:59 ` [PATCH v2 8/8] HID: remove no longer used hid->open field Dmitry Torokhov
2017-06-07 8:45 ` [PATCH v2 0/8] HID: Consolidate serializing ope/close in transport drivers Andy Shevchenko
2017-06-07 13:43 ` Benjamin Tissoires
2017-06-08 11:56 ` Jiri Kosina
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