From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcus Folkesson Subject: [RESEND PATCH 5/6] input: usbtouchscreen: fix deadlock in autosuspend Date: Wed, 28 Feb 2018 14:38:02 +0100 Message-ID: <20180228133803.30040-6-marcus.folkesson@gmail.com> References: <20180228133803.30040-1-marcus.folkesson@gmail.com> Return-path: In-Reply-To: <20180228133803.30040-1-marcus.folkesson@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov , Arvind Yadav Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Marcus Folkesson List-Id: linux-input@vger.kernel.org usb_autopm_get_interface() that is called in usbtouch_open() does an autoresume if the device is suspended. input_dev->mutex used in usbtouch_resume() is in this case already taken by the input subsystem and will cause a deadlock. Signed-off-by: Marcus Folkesson --- drivers/input/touchscreen/usbtouchscreen.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c index 2c41107240de..e964658203d8 100644 --- a/drivers/input/touchscreen/usbtouchscreen.c +++ b/drivers/input/touchscreen/usbtouchscreen.c @@ -54,6 +54,7 @@ #include #include #include +#include #define DRIVER_VERSION "v0.6" @@ -112,6 +113,7 @@ struct usbtouch_usb { struct usb_interface *interface; struct input_dev *input; struct usbtouch_device_info *type; + struct mutex pm_mutex; /* serialize access to open/suspend */ char name[128]; char phys[64]; void *priv; @@ -1455,6 +1457,7 @@ static int usbtouch_open(struct input_dev *input) if (r < 0) goto out; + mutex_lock(&usbtouch->pm_mutex); if (!usbtouch->type->irq_always) { if (usb_submit_urb(usbtouch->irq, GFP_KERNEL)) { r = -EIO; @@ -1464,6 +1467,7 @@ static int usbtouch_open(struct input_dev *input) usbtouch->interface->needs_remote_wakeup = 1; out_put: + mutex_unlock(&usbtouch->pm_mutex); usb_autopm_put_interface(usbtouch->interface); out: return r; @@ -1474,8 +1478,11 @@ static void usbtouch_close(struct input_dev *input) struct usbtouch_usb *usbtouch = input_get_drvdata(input); int r; + mutex_lock(&usbtouch->pm_mutex); if (!usbtouch->type->irq_always) usb_kill_urb(usbtouch->irq); + mutex_lock(&usbtouch->pm_mutex); + r = usb_autopm_get_interface(usbtouch->interface); usbtouch->interface->needs_remote_wakeup = 0; if (!r) @@ -1498,10 +1505,10 @@ static int usbtouch_resume(struct usb_interface *intf) struct input_dev *input = usbtouch->input; int result = 0; - mutex_lock(&input->mutex); + mutex_lock(&usbtouch->pm_mutex); if (input->users || usbtouch->type->irq_always) result = usb_submit_urb(usbtouch->irq, GFP_NOIO); - mutex_unlock(&input->mutex); + mutex_unlock(&usbtouch->pm_mutex); return result; } @@ -1524,10 +1531,10 @@ static int usbtouch_reset_resume(struct usb_interface *intf) } /* restart IO if needed */ - mutex_lock(&input->mutex); + mutex_lock(&usbtouch->pm_mutex); if (input->users) err = usb_submit_urb(usbtouch->irq, GFP_NOIO); - mutex_unlock(&input->mutex); + mutex_unlock(&usbtouch->pm_mutex); return err; } -- 2.16.2