Re: [RESEND PATCH 5/6] input: usbtouchscreen: fix deadlock in autosuspend
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2018-03-17 18:11:21
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On Wed, Feb 28, 2018 at 02:38:02PM +0100, Marcus Folkesson wrote:
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 <marcus.folkesson@gmail.com>
Applied, thank you.
quoted hunk ↗ jump to hunk
--- 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 <linux/usb.h> #include <linux/usb/input.h> #include <linux/hid.h> +#include <linux/mutex.h> #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
-- Dmitry