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authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-05 01:22:04 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-05 01:22:04 +0400
commit1c08232cfe5e68c6234305a3abb64d52d89c9ead (patch)
treeffba8b76685d26e719c20591e7b2b04468dd8507 /drivers/media/rc/imon.c
parent8db72a7d7268630e04ec285fbd3e90733b2eddf9 (diff)
parentb730011061e2805a46b7291e708b6caaf2be6869 (diff)
downloadlinux-1c08232cfe5e68c6234305a3abb64d52d89c9ead.tar.xz
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: [media] ngene: Fix CI data transfer regression Fix CI data transfer regression introduced by previous cleanup. [media] v4l: make sure drivers supply a zeroed struct v4l2_subdev [media] Missing frontend config for LME DM04/QQBOX [media] rc_core: avoid kernel oops when rmmod saa7134 [media] imon: add conditional locking in change_protocol [media] rc: show RC_TYPE_OTHER in sysfs [media] ite-cir: modular build on ppc requires delay.h include [media] mceusb: add Dell transceiver ID
Diffstat (limited to 'drivers/media/rc/imon.c')
-rw-r--r--drivers/media/rc/imon.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index ebd68edf5b24..8fc0f081b470 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -46,7 +46,7 @@
#define MOD_AUTHOR "Jarod Wilson <jarod@wilsonet.com>"
#define MOD_DESC "Driver for SoundGraph iMON MultiMedia IR/Display"
#define MOD_NAME "imon"
-#define MOD_VERSION "0.9.2"
+#define MOD_VERSION "0.9.3"
#define DISPLAY_MINOR_BASE 144
#define DEVICE_NAME "lcd%d"
@@ -460,8 +460,9 @@ static int display_close(struct inode *inode, struct file *file)
}
/**
- * Sends a packet to the device -- this function must be called
- * with ictx->lock held.
+ * Sends a packet to the device -- this function must be called with
+ * ictx->lock held, or its unlock/lock sequence while waiting for tx
+ * to complete can/will lead to a deadlock.
*/
static int send_packet(struct imon_context *ictx)
{
@@ -991,12 +992,21 @@ static void imon_touch_display_timeout(unsigned long data)
* the iMON remotes, and those used by the Windows MCE remotes (which is
* really just RC-6), but only one or the other at a time, as the signals
* are decoded onboard the receiver.
+ *
+ * This function gets called two different ways, one way is from
+ * rc_register_device, for initial protocol selection/setup, and the other is
+ * via a userspace-initiated protocol change request, either by direct sysfs
+ * prodding or by something like ir-keytable. In the rc_register_device case,
+ * the imon context lock is already held, but when initiated from userspace,
+ * it is not, so we must acquire it prior to calling send_packet, which
+ * requires that the lock is held.
*/
static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
{
int retval;
struct imon_context *ictx = rc->priv;
struct device *dev = ictx->dev;
+ bool unlock = false;
unsigned char ir_proto_packet[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x86 };
@@ -1029,6 +1039,11 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet));
+ if (!mutex_is_locked(&ictx->lock)) {
+ unlock = true;
+ mutex_lock(&ictx->lock);
+ }
+
retval = send_packet(ictx);
if (retval)
goto out;
@@ -1037,6 +1052,9 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
ictx->pad_mouse = false;
out:
+ if (unlock)
+ mutex_unlock(&ictx->lock);
+
return retval;
}
@@ -2134,6 +2152,7 @@ static struct imon_context *imon_init_intf0(struct usb_interface *intf)
goto rdev_setup_failed;
}
+ mutex_unlock(&ictx->lock);
return ictx;
rdev_setup_failed:
@@ -2205,6 +2224,7 @@ static struct imon_context *imon_init_intf1(struct usb_interface *intf,
goto urb_submit_failed;
}
+ mutex_unlock(&ictx->lock);
return ictx;
urb_submit_failed:
@@ -2299,6 +2319,8 @@ static int __devinit imon_probe(struct usb_interface *interface,
usb_set_intfdata(interface, ictx);
if (ifnum == 0) {
+ mutex_lock(&ictx->lock);
+
if (product == 0xffdc && ictx->rf_device) {
sysfs_err = sysfs_create_group(&interface->dev.kobj,
&imon_rf_attr_group);
@@ -2309,13 +2331,14 @@ static int __devinit imon_probe(struct usb_interface *interface,
if (ictx->display_supported)
imon_init_display(ictx, interface);
+
+ mutex_unlock(&ictx->lock);
}
dev_info(dev, "iMON device (%04x:%04x, intf%d) on "
"usb<%d:%d> initialized\n", vendor, product, ifnum,
usbdev->bus->busnum, usbdev->devnum);
- mutex_unlock(&ictx->lock);
mutex_unlock(&driver_lock);
return 0;