3.16.36-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
commit 972e6a993f278b416a8ee3ec65475724fc36feb2 upstream.
The usbhid driver has inconsistently duplicated code in its post-reset,
resume, and reset-resume pathways.
reset-resume doesn't check HID_STARTED before trying to
restart the I/O queues.
resume fails to clear the HID_SUSPENDED flag if HID_STARTED
isn't set.
resume calls usbhid_restart_queues() with usbhid->lock held
and the others call it without holding the lock.
The first item in particular causes a problem following a reset-resume
if the driver hasn't started up its I/O. URB submission fails because
usbhid->urbin is NULL, and this triggers an unending reset-retry loop.
This patch fixes the problem by creating a new subroutine,
hid_restart_io(), to carry out all the common activities. It also
adds some checks that were missing in the original code:
After a reset, there's no need to clear any halted endpoints.
After a resume, if a reset is pending there's no need to
restart any I/O until the reset is finished.
After a resume, if the interrupt-IN endpoint is halted there's
no need to submit the input URB until the halt has been
cleared.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Daniel Fraga <fragabr@xxxxxxxxx>
Tested-by: Daniel Fraga <fragabr@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/hid/usbhid/hid-core.c | 73 ++++++++++++++++++++++---------------------
1 file changed, 37 insertions(+), 36 deletions(-)
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -955,14 +955,6 @@ static int usbhid_output_report(struct h
return ret;
}
-static void usbhid_restart_queues(struct usbhid_device *usbhid)
-{
- if (usbhid->urbout && !test_bit(HID_OUT_RUNNING, &usbhid->iofl))
- usbhid_restart_out_queue(usbhid);
- if (!test_bit(HID_CTRL_RUNNING, &usbhid->iofl))
- usbhid_restart_ctrl_queue(usbhid);
-}
-
static void hid_free_buffers(struct usb_device *dev, struct hid_device *hid)
{
struct usbhid_device *usbhid = hid->driver_data;
@@ -1408,6 +1400,37 @@ static void hid_cease_io(struct usbhid_d
usb_kill_urb(usbhid->urbout);
}
+static void hid_restart_io(struct hid_device *hid)
+{
+ struct usbhid_device *usbhid = hid->driver_data;
+ int clear_halt = test_bit(HID_CLEAR_HALT, &usbhid->iofl);
+ int reset_pending = test_bit(HID_RESET_PENDING, &usbhid->iofl);
+
+ spin_lock_irq(&usbhid->lock);
+ clear_bit(HID_SUSPENDED, &usbhid->iofl);
+ usbhid_mark_busy(usbhid);
+
+ if (clear_halt || reset_pending)
+ schedule_work(&usbhid->reset_work);
+ usbhid->retry_delay = 0;
+ spin_unlock_irq(&usbhid->lock);
+
+ if (reset_pending || !test_bit(HID_STARTED, &usbhid->iofl))
+ return;
+
+ if (!clear_halt) {
+ if (hid_start_in(hid) < 0)
+ hid_io_error(hid);
+ }
+
+ spin_lock_irq(&usbhid->lock);
+ if (usbhid->urbout && !test_bit(HID_OUT_RUNNING, &usbhid->iofl))
+ usbhid_restart_out_queue(usbhid);
+ if (!test_bit(HID_CTRL_RUNNING, &usbhid->iofl))
+ usbhid_restart_ctrl_queue(usbhid);
+ spin_unlock_irq(&usbhid->lock);
+}
+
/* Treat USB reset pretty much the same as suspend/resume */
static int hid_pre_reset(struct usb_interface *intf)
{
@@ -1457,14 +1480,14 @@ static int hid_post_reset(struct usb_int
return 1;
}
+ /* No need to do another reset or clear a halted endpoint */
spin_lock_irq(&usbhid->lock);
clear_bit(HID_RESET_PENDING, &usbhid->iofl);
+ clear_bit(HID_CLEAR_HALT, &usbhid->iofl);
spin_unlock_irq(&usbhid->lock);
hid_set_idle(dev, intf->cur_altsetting->desc.bInterfaceNumber, 0, 0);
- status = hid_start_in(hid);
- if (status < 0)
- hid_io_error(hid);
- usbhid_restart_queues(usbhid);
+
+ hid_restart_io(hid);
return 0;
}
@@ -1487,25 +1510,9 @@ void usbhid_put_power(struct hid_device
#ifdef CONFIG_PM
static int hid_resume_common(struct hid_device *hid, bool driver_suspended)
{
- struct usbhid_device *usbhid = hid->driver_data;
- int status;
-
- spin_lock_irq(&usbhid->lock);
- clear_bit(HID_SUSPENDED, &usbhid->iofl);
- usbhid_mark_busy(usbhid);
-
- if (test_bit(HID_CLEAR_HALT, &usbhid->iofl) ||
- test_bit(HID_RESET_PENDING, &usbhid->iofl))
- schedule_work(&usbhid->reset_work);
- usbhid->retry_delay = 0;
-
- usbhid_restart_queues(usbhid);
- spin_unlock_irq(&usbhid->lock);
-
- status = hid_start_in(hid);
- if (status < 0)
- hid_io_error(hid);
+ int status = 0;
+ hid_restart_io(hid);
if (driver_suspended && hid->driver && hid->driver->resume)
status = hid->driver->resume(hid);
return status;
@@ -1574,12 +1581,8 @@ static int hid_suspend(struct usb_interf
static int hid_resume(struct usb_interface *intf)
{
struct hid_device *hid = usb_get_intfdata (intf);
- struct usbhid_device *usbhid = hid->driver_data;
int status;
- if (!test_bit(HID_STARTED, &usbhid->iofl))
- return 0;
-
status = hid_resume_common(hid, true);
dev_dbg(&intf->dev, "resume status %d\n", status);
return 0;
@@ -1588,10 +1591,8 @@ static int hid_resume(struct usb_interfa
static int hid_reset_resume(struct usb_interface *intf)
{
struct hid_device *hid = usb_get_intfdata(intf);
- struct usbhid_device *usbhid = hid->driver_data;
int status;
- clear_bit(HID_SUSPENDED, &usbhid->iofl);
status = hid_post_reset(intf);
if (status >= 0 && hid->driver && hid->driver->reset_resume) {
int ret = hid->driver->reset_resume(hid);
--
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