[media] imon: don't wedge hardware after early callbacks

This patch is just a minor update to one titled "imon: Input from ffdc
device type ignored" from Corinna Vinschen. An earlier patch to prevent
an oops when we got early callbacks also has the nasty side-effect of
wedging imon hardware, as we don't acknowledge the urb. Rework the check
slightly here to bypass processing the packet, as the driver isn't yet
fully initialized, but still acknowlege the urb and submit a new rx_urb.
Do this for both interfaces -- irrelevant for ffdc hardware, but
relevant for newer hardware, though newer hardware doesn't spew the
constant stream of data as soon as the hardware is initialized like the
older ffdc devices, so they'd be less likely to trigger this anyway...

Tested with both an ffdc device and an 0042 device.

Reported-by: Corinna Vinschen <vinschen@redhat.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index 6ed96465137a..3f175ebe2766 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -47,7 +47,7 @@
 #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     "0.9.3"
+#define MOD_VERSION     "0.9.4"
 
 #define DISPLAY_MINOR_BASE      144
 #define DEVICE_NAME     "lcd%d"
@@ -1658,9 +1658,17 @@ static void usb_rx_callback_intf0(struct urb *urb)
                 return;
 
         ictx = (struct imon_context *)urb->context;
-        if (!ictx || !ictx->dev_present_intf0)
+        if (!ictx)
                 return;
 
+        /*
+         * if we get a callback before we're done configuring the hardware, we
+         * can't yet process the data, as there's nowhere to send it, but we
+         * still need to submit a new rx URB to avoid wedging the hardware
+         */
+        if (!ictx->dev_present_intf0)
+                goto out;
+
         switch (urb->status) {
         case -ENOENT:           /* usbcore unlink successful! */
                 return;
@@ -1678,6 +1686,7 @@ static void usb_rx_callback_intf0(struct urb *urb)
                 break;
         }
 
+out:
         usb_submit_urb(ictx->rx_urb_intf0, GFP_ATOMIC);
 }
 
@@ -1690,9 +1699,17 @@ static void usb_rx_callback_intf1(struct urb *urb)
                 return;
 
         ictx = (struct imon_context *)urb->context;
-        if (!ictx || !ictx->dev_present_intf1)
+        if (!ictx)
                 return;
 
+        /*
+         * if we get a callback before we're done configuring the hardware, we
+         * can't yet process the data, as there's nowhere to send it, but we
+         * still need to submit a new rx URB to avoid wedging the hardware
+         */
+        if (!ictx->dev_present_intf1)
+                goto out;
+
         switch (urb->status) {
         case -ENOENT:           /* usbcore unlink successful! */
                 return;
@@ -1710,6 +1727,7 @@ static void usb_rx_callback_intf1(struct urb *urb)
                 break;
         }
 
+out:
         usb_submit_urb(ictx->rx_urb_intf1, GFP_ATOMIC);
 }
 
@@ -2242,7 +2260,7 @@ find_endpoint_failed:
         mutex_unlock(&ictx->lock);
         usb_free_urb(rx_urb);
 rx_urb_alloc_failed:
-        dev_err(ictx->dev, "unable to initialize intf0, err %d\n", ret);
+        dev_err(ictx->dev, "unable to initialize intf1, err %d\n", ret);
 
         return NULL;
 }