Post AadoLZPbXimD3ExArQ by MishaalRahman@androiddev.social
(DIR) More posts by MishaalRahman@androiddev.social
(DIR) Post #AaRZ0zV99vKaJSdFuC by MishaalRahman@androiddev.social
2023-10-05T00:47:52Z
0 likes, 0 repeats
Since I'm not gonna have my own Pixel 8 for a while, I might as well put this out there so someone else can test it ASAP:You might be able to enable DisplayPort Alternate Mode (ie. display output over USB-C) if you root the device. That's because it seems to be disabled at a software, not hardware, level unlike previous Pixels.You can see here from a dump of husky (code-name for the Pixel 8 Pro) that the property persist.vendor.usb.displayport.enabled is set to 0.
(DIR) Post #AaRZ36qGpz49euWTWC by MishaalRahman@androiddev.social
2023-10-05T00:48:18Z
0 likes, 0 repeats
This property is read by the init.zuma.usb.rc file, which is the USB config file for the Tensor G3-series devices (zuma). Since this property is set to 0, then DisplayPort is disabled.Thus, if you root the phone and override this property (eg. via setprop persist.vendor.usb.displayport.enabled 1), then this may be enough to enable DisplayPort Alternate Mode.There's even a separate display config for when DisplayPort is enabled, under /vendor/etc/displayconfig/display_port_0.xml.
(DIR) Post #AaRZ46msWhBxmLPdq4 by MishaalRahman@androiddev.social
2023-10-05T00:48:28Z
0 likes, 0 repeats
Anyway, if you manage to get display output working using what I said, please let me know! If it does work, then that means Google can enable display output via an OTA update.I'm aware that current carrier store models don't support display output, and that some are reporting (https://twitter.com/howtomen/status/1709625695486214486) that it doesn't as well (eg. below). However, it's true that they don't support it right now, but that doesn't mean it can never be enabled.
(DIR) Post #AaUzRFAxFOTOnO6UzI by MishaalRahman@androiddev.social
2023-10-06T16:28:08Z
0 likes, 0 repeats
I have some bad news to share: This method didn't work.A brave person with a Pixel 8 Pro (who wants to stay anonymous) reached out to me, and we were able to easily root the device. We overrode the property and verified the sysfs files were changed, too, but sadly there was still no display output. This person used a USB-C to HDMI adapter and cables that they verified worked with another device (a Samsung), so it's not a cable problem.
(DIR) Post #AaUzRxEhQpc3RkC6vw by MishaalRahman@androiddev.social
2023-10-06T16:28:13Z
0 likes, 0 repeats
I'm not fully ruling out display output support, but it's not looking good. Once Google releases the Pixel 8's kernel/device tree sources next week, we should hopefully find more clues.
(DIR) Post #AaV2XywcIDU8LRImiO by SomeGadgetGuy@techhub.social
2023-10-06T17:02:58Z
0 likes, 0 repeats
@MishaalRahman Google KILLING me with this one. It's such a useful feature for a premium phone to lack.
(DIR) Post #AaV4P7mAHvzf2MJk48 by fireborn@dragonscave.space
2023-10-06T17:23:47Z
0 likes, 0 repeats
@MishaalRahman What does disabling features of the hardware at a software level actually accomplish? I know Google isn't the only company doing this, but I hate it every time I see it.
(DIR) Post #AaV5A4K8wMFBwQay2K by MishaalRahman@androiddev.social
2023-10-06T17:32:16Z
0 likes, 0 repeats
@fireborn because the current experience of display output would just be screen mirroring, which isn't a great experience. They likely want to fully build out a desktop mode experience before enabling display output
(DIR) Post #AaV5TVqkp7JsoW7WfA by fireborn@dragonscave.space
2023-10-06T17:35:47Z
0 likes, 0 repeats
@MishaalRahman But if that's actually the experience someone wants, display mirroring, then what advantage is there to disabling it? People who don't want to use it aren't obligated to. This artificial limiting of hardware functions is stupid from anyone who does it.
(DIR) Post #AaaY3GYyhbIOdhhxq4 by fat8893@mastodon.social
2023-10-09T08:49:32Z
0 likes, 0 repeats
@MishaalRahman Darn, I was already anticipating about the new Pixel 8 series because of video output. 😓😓
(DIR) Post #AadoLZPbXimD3ExArQ by MishaalRahman@androiddev.social
2023-10-10T22:36:12Z
0 likes, 0 repeats
Here's the code change (https://android.googlesource.com/device/google/zuma/+/2173dc37da793599239a974d8f7bc40b2bf1ee80%5E%21/#F0) that added this system property. It seems that USB-C DisplayPort Alternate Mode is currently only enabled on userdebug/eng builds. I'm not sure why it doesn't work when spoofing that property on user builds, though.