[3.8.y.z extended stable] Patch "[media] ivtv: Fix Oops when no firmware is loaded" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    [media] ivtv: Fix Oops when no firmware is loaded

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.27.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 925c5c2db905a79e84715b8f9838e48ae83986fc Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai at suse.de>
Date: Mon, 5 May 2014 11:20:05 -0300
Subject: [media] ivtv: Fix Oops when no firmware is loaded

commit deb29e90221a6d4417aa67be971613c353180331 upstream.

When ivtv PCM device is accessed at the state where no firmware is
loaded, it oopses like:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
  IP: [<ffffffffa049a881>] try_mailbox.isra.0+0x11/0x50 [ivtv]
  Call Trace:
    [<ffffffffa049aa20>] ivtv_api_call+0x160/0x6b0 [ivtv]
    [<ffffffffa049af86>] ivtv_api+0x16/0x40 [ivtv]
    [<ffffffffa049b10c>] ivtv_vapi+0xac/0xc0 [ivtv]
    [<ffffffffa049d40d>] ivtv_start_v4l2_encode_stream+0x19d/0x630 [ivtv]
    [<ffffffffa0530653>] snd_ivtv_pcm_capture_open+0x173/0x1c0 [ivtv_alsa]
    [<ffffffffa04526f1>] snd_pcm_open_substream+0x51/0x100 [snd_pcm]
    [<ffffffffa0452853>] snd_pcm_open+0xb3/0x260 [snd_pcm]
    [<ffffffffa0452a37>] snd_pcm_capture_open+0x37/0x50 [snd_pcm]
    [<ffffffffa033f557>] snd_open+0xa7/0x1e0 [snd]
    [<ffffffff8118a628>] chrdev_open+0x88/0x1d0
    [<ffffffff811840be>] do_dentry_open+0x1de/0x270
    [<ffffffff81193a73>] do_last+0x1c3/0xec0
    [<ffffffff81194826>] path_openat+0xb6/0x670
    [<ffffffff81195b65>] do_filp_open+0x35/0x80
    [<ffffffff81185449>] do_sys_open+0x129/0x210
    [<ffffffff815b782d>] system_call_fastpath+0x1a/0x1f

This patch adds the check of firmware at PCM open callback like other
open callbacks of this driver.

Bugzilla: https://apibugzilla.novell.com/show_bug.cgi?id=875440

Signed-off-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab at samsung.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/media/pci/ivtv/ivtv-alsa-pcm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c
index e1863db..7a9b98b 100644
--- a/drivers/media/pci/ivtv/ivtv-alsa-pcm.c
+++ b/drivers/media/pci/ivtv/ivtv-alsa-pcm.c
@@ -159,6 +159,12 @@ static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)

 	/* Instruct the CX2341[56] to start sending packets */
 	snd_ivtv_lock(itvsc);
+
+	if (ivtv_init_on_first_open(itv)) {
+		snd_ivtv_unlock(itvsc);
+		return -ENXIO;
+	}
+
 	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];

 	v4l2_fh_init(&item.fh, s->vdev);
--
1.9.1