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From: Marcus Folkesson <marcus.folkesson@gmail.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
	Marcus Folkesson <marcus.folkesson@gmail.com>
Subject: [RESEND PATCH 4/6] input: pegasus_notetaker: do not rely on input_dev->users
Date: Wed, 28 Feb 2018 14:38:01 +0100	[thread overview]
Message-ID: <20180228133803.30040-5-marcus.folkesson@gmail.com> (raw)
In-Reply-To: <20180228133803.30040-1-marcus.folkesson@gmail.com>

If the device is unused and suspended, a call to open will cause the
device to autoresume through the call to usb_autopm_get_interface().

input_dev->users is already incremented by the input subsystem,
therefore this expression will always be evaluated to true:

	if (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
		retval = -EIO;

The same URB will then be fail when resubmitted in pegasus_open().

Introduce pegasus->is_open to keep track of the state instead.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---
 drivers/input/tablet/pegasus_notetaker.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/input/tablet/pegasus_notetaker.c b/drivers/input/tablet/pegasus_notetaker.c
index 9ab1ed5e20e7..74c93e09c337 100644
--- a/drivers/input/tablet/pegasus_notetaker.c
+++ b/drivers/input/tablet/pegasus_notetaker.c
@@ -80,6 +80,7 @@ struct pegasus {
 
 	/* serialize access to open/suspend */
 	struct mutex pm_mutex;
+	bool is_open;
 
 	char name[128];
 	char phys[64];
@@ -232,6 +233,7 @@ static int pegasus_open(struct input_dev *dev)
 	if (error)
 		goto err_kill_urb;
 
+	pegasus->is_open = 1;
 	mutex_unlock(&pegasus->pm_mutex);
 	return 0;
 
@@ -251,6 +253,7 @@ static void pegasus_close(struct input_dev *dev)
 	mutex_lock(&pegasus->pm_mutex);
 	usb_kill_urb(pegasus->irq);
 	cancel_work_sync(&pegasus->init);
+	pegasus->is_open = 0;
 	mutex_unlock(&pegasus->pm_mutex);
 
 	usb_autopm_put_interface(pegasus->intf);
@@ -415,7 +418,7 @@ static int pegasus_resume(struct usb_interface *intf)
 	int retval = 0;
 
 	mutex_lock(&pegasus->pm_mutex);
-	if (pegasus->dev->users && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
+	if (pegasus->is_open && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
 		retval = -EIO;
 	mutex_unlock(&pegasus->pm_mutex);
 
@@ -428,7 +431,7 @@ static int pegasus_reset_resume(struct usb_interface *intf)
 	int retval = 0;
 
 	mutex_lock(&pegasus->pm_mutex);
-	if (pegasus->dev->users) {
+	if (pegasus->is_open) {
 		retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
 					  NOTETAKER_LED_MOUSE);
 		if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
-- 
2.16.2

  parent reply	other threads:[~2018-02-28 13:38 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-28 13:37 Fix deadlocks in autosuspend Marcus Folkesson
2018-02-28 13:37 ` [RESEND PATCH 1/6] input: synaptics_usb: fix deadlock " Marcus Folkesson
2018-03-17 18:10   ` Dmitry Torokhov
2018-02-28 13:37 ` [RESEND PATCH 2/6] input: synaptics_usb: do not rely on input_dev->users Marcus Folkesson
2018-03-17 18:10   ` Dmitry Torokhov
2018-02-28 13:38 ` [RESEND PATCH 3/6] input: pagasus_notetaker: fix deadlock in autosuspend Marcus Folkesson
2018-03-17 18:10   ` Dmitry Torokhov
2018-02-28 13:38 ` Marcus Folkesson [this message]
2018-03-17 18:11   ` [RESEND PATCH 4/6] input: pegasus_notetaker: do not rely on input_dev->users Dmitry Torokhov
2018-02-28 13:38 ` [RESEND PATCH 5/6] input: usbtouchscreen: fix deadlock in autosuspend Marcus Folkesson
2018-03-17 18:11   ` Dmitry Torokhov
2018-02-28 13:38 ` [RESEND PATCH 6/6] input: usbtouchscreen: do not rely on input_dev->users Marcus Folkesson
2018-03-17 18:11   ` Dmitry Torokhov
2018-03-16 13:41 ` Fix deadlocks in autosuspend Marcus Folkesson

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