From fde5be353e872fe6088d2b1951e56cdfda2042ff Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Sun, 23 Nov 2008 12:03:20 +0100 Subject: [PATCH] HID: remove setup mutex, fix possible deadlock It causes recursive locking warning and is unneeded after introduction of STARTED flag. * Resume vs. stop is effectively solved by DISCONNECT flag. * No problem in suspend vs. start -- urb is submitted even after open which is possible after connect which is called after start. * Resume vs. start solved by STARTED flag. * Suspend vs. stop -- no problem in killing urb and timer twice. Reported-by: Alan Stern Signed-off-by: Jiri Slaby Signed-off-by: Jiri Kosina --- drivers/hid/usbhid/hid-core.c | 18 ++---------------- drivers/hid/usbhid/usbhid.h | 1 - 2 files changed, 2 insertions(+), 17 deletions(-) diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c index d746bf8284d..606369ea24c 100644 --- a/drivers/hid/usbhid/hid-core.c +++ b/drivers/hid/usbhid/hid-core.c @@ -796,7 +796,6 @@ static int usbhid_start(struct hid_device *hid) if (insize > HID_MAX_BUFFER_SIZE) insize = HID_MAX_BUFFER_SIZE; - mutex_lock(&usbhid->setup); if (hid_alloc_buffers(dev, hid)) { ret = -ENOMEM; goto fail; @@ -876,7 +875,6 @@ static int usbhid_start(struct hid_device *hid) hid_dump_device(hid); set_bit(HID_STARTED, &usbhid->iofl); - mutex_unlock(&usbhid->setup); return 0; @@ -888,7 +886,6 @@ fail: usbhid->urbout = NULL; usbhid->urbctrl = NULL; hid_free_buffers(dev, hid); - mutex_unlock(&usbhid->setup); return ret; } @@ -899,7 +896,6 @@ static void usbhid_stop(struct hid_device *hid) if (WARN_ON(!usbhid)) return; - mutex_lock(&usbhid->setup); clear_bit(HID_STARTED, &usbhid->iofl); spin_lock_irq(&usbhid->inlock); /* Sync with error handler */ set_bit(HID_DISCONNECTED, &usbhid->iofl); @@ -928,7 +924,6 @@ static void usbhid_stop(struct hid_device *hid) usbhid->urbout = NULL; hid_free_buffers(hid_to_usb_dev(hid), hid); - mutex_unlock(&usbhid->setup); } static struct hid_ll_driver usb_hid_driver = { @@ -1016,7 +1011,6 @@ static int hid_probe(struct usb_interface *intf, const struct usb_device_id *id) hid->driver_data = usbhid; usbhid->hid = hid; - mutex_init(&usbhid->setup); /* needed on suspend/resume */ ret = hid_add_device(hid); if (ret) { @@ -1051,18 +1045,14 @@ static int hid_suspend(struct usb_interface *intf, pm_message_t message) struct hid_device *hid = usb_get_intfdata (intf); struct usbhid_device *usbhid = hid->driver_data; - mutex_lock(&usbhid->setup); - if (!test_bit(HID_STARTED, &usbhid->iofl)) { - mutex_unlock(&usbhid->setup); + if (!test_bit(HID_STARTED, &usbhid->iofl)) return 0; - } spin_lock_irq(&usbhid->inlock); /* Sync with error handler */ set_bit(HID_SUSPENDED, &usbhid->iofl); spin_unlock_irq(&usbhid->inlock); del_timer_sync(&usbhid->io_retry); usb_kill_urb(usbhid->urbin); - mutex_unlock(&usbhid->setup); dev_dbg(&intf->dev, "suspend\n"); return 0; } @@ -1073,16 +1063,12 @@ static int hid_resume(struct usb_interface *intf) struct usbhid_device *usbhid = hid->driver_data; int status; - mutex_lock(&usbhid->setup); - if (!test_bit(HID_STARTED, &usbhid->iofl)) { - mutex_unlock(&usbhid->setup); + if (!test_bit(HID_STARTED, &usbhid->iofl)) return 0; - } clear_bit(HID_SUSPENDED, &usbhid->iofl); usbhid->retry_delay = 0; status = hid_start_in(hid); - mutex_unlock(&usbhid->setup); dev_dbg(&intf->dev, "resume status %d\n", status); return status; } diff --git a/drivers/hid/usbhid/usbhid.h b/drivers/hid/usbhid/usbhid.h index 55973ff5400..332abcdf995 100644 --- a/drivers/hid/usbhid/usbhid.h +++ b/drivers/hid/usbhid/usbhid.h @@ -74,7 +74,6 @@ struct usbhid_device { dma_addr_t outbuf_dma; /* Output buffer dma */ spinlock_t outlock; /* Output fifo spinlock */ - struct mutex setup; unsigned long iofl; /* I/O flags (CTRL_RUNNING, OUT_RUNNING) */ struct timer_list io_retry; /* Retry timer */ unsigned long stop_retry; /* Time to give up, in jiffies */ -- 2.41.0