[mythtv-users] Cablecard and myth

Gary Buhrmaster gary.buhrmaster at gmail.com
Sat Dec 7 00:00:29 UTC 2013


On Fri, Dec 6, 2013 at 6:15 PM, John Adams <mythtv at onevista.com> wrote:
....
> The problem turned out to be broken firmware in the cable card which
> had been  updated automatically.  A Comcast tier2 engineer solved it
> after 15 days

Good to hear that perseverance with Comcast does
(eventually) pay off.

Do you recall the firmware version that was "bad", and
the currently "good" one displayed in the Prime?  I
have not seen any updates since the beginning of the
year.

Note that if Comcast had to do a revised firmware build
that was not currently deployed, 15 days is actually
quite fast (because it has to go through an entire
validation process).



For others playing along, CableCARDs will automatically
upgrade their firmware when they have managed to download
all the relevant pieces from the headend.   The current version
of the CableCARD firmware (and the current version of any
deployed STB firmware) is constantly being sent in the
appropriate background channels in order to automatically
upgrade any newly deployed (or just turned on) boxes/cards.
The firmware is sent in segments, and eventually all the
segments will be received if your signal quality is adequate,
and then the card (or box) gets upgraded and reboots if the
new firmware passes the check to verify it is properly signed.
It can take hours to get all the segments for the entire image
(which is why, when you get a new STB, it may reboot
a few times while it (slowly) upgrades itself, if you were handed
a box that had been sitting on the shelf for an extended period
and had the older firmware).  Typically, for a new firmware
image (which tends to be rare in itself), the MSO will schedule
the first release in the "middle of the night" so that any reboots
occur at a time with the least impact to the majority of the
customer base.

However, there was a known issue with some (very old)
CableCARD firmware where it was too old to properly initialize
the handshake with the HDHR, so it could not be upgraded
(I do not remember the entire story, but it had to do with a
change in specification).  So, it did not perform the proper
function, but was not allowed to upgrade.  Rock, meet hard
place.  While most of the CableCARDs handed out had more
recent firmware, sometimes one got a bad one.  I believe at
some point SiliconDust provided upgraded firmware to bypass
the issue which would allow the CableCARD to be upgraded
to be able to move forward out of the deadlock.


More information about the mythtv-users mailing list