Kernel Panic Reboots & More

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I have an odd set of issues, which might be related.

My setup is a Tivo Edge (7/31/2020), software version 21.10.2 V6, Comcast cablecard, Sony XBR-55A8F with version 9 Android (latest version, updated 12/26/2020). Connected to a gigabit Lan via an HP Procurve switch, then out through a Comcast Business line.

1. When I switch the TV from Standby, most of the time the TV reports there is no signal on the HDMI port connected to the Tivo. To fix this, I switch input ports on the TV to something else, then back to the port the Tivo is connected to. I suppose this is a HDMI handshake problem.

2. Sometimes when doing some sort of playback (either live or a recorded show), the screen goes black and the Tivo reboots. This started in November. In all but one of the handful of cases, it was pressing the Tivo Info button that appeared to initiate the problem. The very, very strange thing is that every time this has happened, it was between 5pm and 5:30pm Pacific time, and usually between 5:15pm and 5:25pm. I think this is a coincidence. Looking at the Tivo logs (System Info then clear clear, enter enter, 0), it is a (Linux) kernel panic on the Tivo that is the cause, but I could not find a detailed kernel panic log to see what the panic was. Kernel panics are typically (but not always) hardware related.

I have a fan set up to cool the Tivo.

3. Sometimes, after being off for some hours, the Tivo TV power button does not get the TV out of Standby, so I use the Sony remote.

Before all this, I had intermittent audio-video sync problems that I believe the 21.10.2 V6 software fixed.

I have tried several certified HDMI cables, but we misplaced the one that came with the Edge. Currently I am using a Zeskit 8K Ultra HD High Speed 48Gpbs HDMI Cable.

 

I have resolved one of these issues - the lost signal on wakeup problem. The remote not waking my Sony XBR-55A8F from Standby might still be a problem, but the kernel panics seem gone. Details:

After a lot of googling I decided to try an HDMI splitter between the Tivo and the Sony. Note that I am not actually splitting the signal to multiple destinations, but simply using the splitter as a trampoline for the HDMI signal. Stated more directly: an HDMI cable goes from the Tivo to the splitter, and an HDMI cable goes from the splitter to the Sony. Nothing else is connected.

What this seems to do is to present the Tivo with an always-on, always-“active” HDMI listener. And when the Sony comes out of Standby mode, either the splitter notices or the Sony handshakes, and the connection from Sony to Tivo is made - through the intermediary of the splitter.

I have a generally hi-res setup (Tivo asked to do 4k/60fps HDR and also the Sony). The first splitter I tried was the Monoprice Blackbird 4K Pro 1x2 Ultra Slim HDMI Splitter. I believe an important feature to have in the splitter is EDID support - in this case, the Blackbird “learns” the EDID settings from output 1 (the Sony) and tells that to the Tivo. This device solved the wake problem, but I noticed that sometimes with sports and just after switching tuners on the Tivo, there would be digital breakup. So I tried another splitter with specs that implied better overall throughput: the Xantech HDMI 4K 1x2 Splitter. The Blackbird also took a fraction of a second (but noticeable) when I switched tuners, but the Xantech does not.

I use Zeskit MAYA 8K 48Gbps Certified Ultra High Speed HDMI cables for the two connections.

I believe that if one is trying for hi-res video, one needs to use one of these higher quality splitters. Typical ones found on Amazon are around $15-$20. The Blackbird is around $70 and the Xantech $136. If the Xantech does not solve the digital breakup problem (which it seems to have solved) my next two splitters to try would be the AVPro Edge AC-DA12-AUHD-GEN2 18Gbps Distribution Amplifier (which is a splitter and signal amplifier) and the Atlona AT-RON-442 Distribution Amplifier. These are even more expensive, but even better specs.

For now I always wake the Sony with the Sony remote. I suspect the problem is that the Tivo remote (even when set up for the Sony Power and volume buttons) is using RF while the Sony remote seems to do IR. And since using a splitter I haven’t seem any kernel panics.

Note that on one of the Sony sites it has been noted that Tivos mess up Sony Bravias on wake from Standby. They recommend using a CEC disabler, the Lindy HDMI CEC Less Adapter (which I tried, but it didn’t help).

In short: Use a decent splitter to solve HDMI handshake problems between your TV and Tivo Edge.