V4L/DVB: ivtv: Add firmare monitoring and debug mode to ignore firmware problems

>From Ian's e-mail:
When a device is opened the firmware state will be checked. If it isn't
responding then the open will fail with -EIO.  Due to the nature of the
hardware, a single failed check will block everything since we don't know
exactly what has failed. A side effect of this is the blocking of debug
access, so an additional debug level has been created which allows the block
to be bypassed.

Andy Walls' modifications:
I modified Ian's patch to add a separate fw_debug module parameter to change
the driver's behavior, as opposed to using the normal debug module parameter.
The fw_debug module parameter is only available when CONFIG_VIDEO_ADV_DEBUG
is set.
I also made some minor whitespace adjustments and changed some warning
messages to be a bit more specific.  s/happy/glad/g

Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/media/video/ivtv/ivtv-firmware.c b/drivers/media/video/ivtv/ivtv-firmware.c
index a71e8ba306b0..efb288d34ca3 100644
--- a/drivers/media/video/ivtv/ivtv-firmware.c
+++ b/drivers/media/video/ivtv/ivtv-firmware.c
@@ -271,3 +271,49 @@ void ivtv_init_mpeg_decoder(struct ivtv *itv)
 	}
 	ivtv_vapi(itv, CX2341X_DEC_STOP_PLAYBACK, 4, 0, 0, 0, 1);
 }
+
+/* Check firmware running state. The checks fall through
+   allowing multiple failures to be logged. */
+int ivtv_firmware_check(struct ivtv *itv, char *where)
+{
+	int res = 0;
+
+	/* Check encoder is still running */
+	if (ivtv_vapi(itv, CX2341X_ENC_PING_FW, 0) < 0) {
+		IVTV_WARN("Encoder has died : %s\n", where);
+		res = -1;
+	}
+
+	/* Also check audio. Only check if not in use & encoder is okay */
+	if (!res && !atomic_read(&itv->capturing) &&
+	    (!atomic_read(&itv->decoding) ||
+	     (atomic_read(&itv->decoding) < 2 && test_bit(IVTV_F_I_DEC_YUV,
+							     &itv->i_flags)))) {
+
+		if (ivtv_vapi(itv, CX2341X_ENC_MISC, 1, 12) < 0) {
+			IVTV_WARN("Audio has died (Encoder OK) : %s\n", where);
+			res = -2;
+		}
+	}
+
+	if (itv->v4l2_cap & V4L2_CAP_VIDEO_OUTPUT) {
+		/* Second audio check. Skip if audio already failed */
+		if (res != -2 && read_dec(0x100) != read_dec(0x104)) {
+			/* Wait & try again to be certain. */
+			ivtv_msleep_timeout(14, 0);
+			if (read_dec(0x100) != read_dec(0x104)) {
+				IVTV_WARN("Audio has died (Decoder) : %s\n",
+					  where);
+				res = -1;
+			}
+		}
+
+		/* Check decoder is still running */
+		if (ivtv_vapi(itv, CX2341X_DEC_PING_FW, 0) < 0) {
+			IVTV_WARN("Decoder has died : %s\n", where);
+			res = -1;
+		}
+	}
+
+	return res;
+}