From b8a7cc4b5e5a0681fdeffe92b613e3e4eb769801 Mon Sep 17 00:00:00 2001 From: Marcus Folkesson Date: Sat, 17 Mar 2018 10:49:46 -0700 Subject: [PATCH] Input: synaptics_usb - fix deadlock in autosuspend usb_autopm_get_interface() that is called in synusb_open() does an autoresume if the device is suspended. input_dev->mutex used in synusb_resume() is in this case already taken by the input subsystem and will cause a deadlock. Signed-off-by: Marcus Folkesson Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/synaptics_usb.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/input/mouse/synaptics_usb.c b/drivers/input/mouse/synaptics_usb.c index cb7d15d826d0..2c66913cf5a2 100644 --- a/drivers/input/mouse/synaptics_usb.c +++ b/drivers/input/mouse/synaptics_usb.c @@ -82,6 +82,9 @@ struct synusb { struct urb *urb; unsigned char *data; + /* serialize access to open/suspend */ + struct mutex pm_mutex; + /* input device related data structures */ struct input_dev *input; char name[128]; @@ -252,6 +255,7 @@ static int synusb_open(struct input_dev *dev) return retval; } + mutex_lock(&synusb->pm_mutex); retval = usb_submit_urb(synusb->urb, GFP_KERNEL); if (retval) { dev_err(&synusb->intf->dev, @@ -264,6 +268,7 @@ static int synusb_open(struct input_dev *dev) synusb->intf->needs_remote_wakeup = 1; out: + mutex_unlock(&synusb->pm_mutex); usb_autopm_put_interface(synusb->intf); return retval; } @@ -275,8 +280,10 @@ static void synusb_close(struct input_dev *dev) autopm_error = usb_autopm_get_interface(synusb->intf); + mutex_lock(&synusb->pm_mutex); usb_kill_urb(synusb->urb); synusb->intf->needs_remote_wakeup = 0; + mutex_unlock(&synusb->pm_mutex); if (!autopm_error) usb_autopm_put_interface(synusb->intf); @@ -315,6 +322,7 @@ static int synusb_probe(struct usb_interface *intf, synusb->udev = udev; synusb->intf = intf; synusb->input = input_dev; + mutex_init(&synusb->pm_mutex); synusb->flags = id->driver_info; if (synusb->flags & SYNUSB_COMBO) { @@ -466,11 +474,10 @@ static void synusb_disconnect(struct usb_interface *intf) static int synusb_suspend(struct usb_interface *intf, pm_message_t message) { struct synusb *synusb = usb_get_intfdata(intf); - struct input_dev *input_dev = synusb->input; - mutex_lock(&input_dev->mutex); + mutex_lock(&synusb->pm_mutex); usb_kill_urb(synusb->urb); - mutex_unlock(&input_dev->mutex); + mutex_unlock(&synusb->pm_mutex); return 0; } @@ -481,14 +488,14 @@ static int synusb_resume(struct usb_interface *intf) struct input_dev *input_dev = synusb->input; int retval = 0; - mutex_lock(&input_dev->mutex); + mutex_lock(&synusb->pm_mutex); if ((input_dev->users || (synusb->flags & SYNUSB_IO_ALWAYS)) && usb_submit_urb(synusb->urb, GFP_NOIO) < 0) { retval = -EIO; } - mutex_unlock(&input_dev->mutex); + mutex_unlock(&synusb->pm_mutex); return retval; } @@ -496,9 +503,8 @@ static int synusb_resume(struct usb_interface *intf) static int synusb_pre_reset(struct usb_interface *intf) { struct synusb *synusb = usb_get_intfdata(intf); - struct input_dev *input_dev = synusb->input; - mutex_lock(&input_dev->mutex); + mutex_lock(&synusb->pm_mutex); usb_kill_urb(synusb->urb); return 0; @@ -515,7 +521,7 @@ static int synusb_post_reset(struct usb_interface *intf) retval = -EIO; } - mutex_unlock(&input_dev->mutex); + mutex_unlock(&synusb->pm_mutex); return retval; } -- 2.20.1