Update Tyr Info

Now that Tyr is upstream, the process for contributing has changed.
Update the documentation about the development process to help
new contributors.

Also, while here, update progress in the downstream driver.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>

Author: deborahbrouwer

src/Tyr-GPU-Driver.md

@@ -16,10 +16,14 @@ ecosystem. It will probably take a couple of years for Tyr to fully pick up.
 
 ## Where is Tyr developed?
 
-The development of Tyr takes place both upstream, through our [latest
-submission](https://lore.kernel.org/rust-for-linux/20250627-tyr-v1-1-cb5f4c6ced46@collabora.com/)
-— and downstream, on the `tyr-next` branch at the [Panfrost Gitlab
-repository](https://gitlab.freedesktop.org/panfrost/linux).
+Tyr is developed both upstream and downstream:
+
+### Upstream
+The initial skeleton of the Tyr driver is now upstream. Submissions against the upstream Tyr driver should go to the [rust-for-linux](https://lore.kernel.org/rust-for-linux/) mailing list. If the submission is larger and/or needs to be pre-reviewed, open a merge request against the [tyr-for-upstream](https://gitlab.freedesktop.org/panfrost/linux/-/tree/tyr-for-upstream) branch in the [panfrost/linux](https://gitlab.freedesktop.org/panfrost/linux) repository.
+
+
+### Downstream
+A more complete implementation of the Tyr driver is also available in the [tyr-dev](https://gitlab.freedesktop.org/panfrost/linux/-/tree/tyr-dev) branch. Make submissions against the downstream Tyr driver by opening a merge request against `tyr-dev`. It's expected that `tyr-dev` will be significantly refactored before upstreaming.
 
 This split is unfortunately necessary as we do not have the required
 infrastructure in upstream yet, although our plan is to eventually migrate to
@@ -41,20 +45,15 @@ functional driver with the abstractions that are currently being proposed.
 
 ## What is the current status of the driver?
 
-The current upstream submission can power up the GPU and probe the device on an
+The current upstream driver can power up the GPU and probe the device on an
 RK3588 system-on-chip. This lets us read a few sections of ROM in the GPU,
 which in turn lets us provide this information to userspace by means of a
 `DRM_IOCTL_PANTHOR_DEV_QUERY` call.
 
 This is all that can be done for now in upstream code, at least until the Micro
 Controller Unit can be made to work.
 
-Our downstream branch (`tyr-next`) can submit small parcels of work to the GPU,
-and we will soon be able to submit more elaborate workflows. We hope to see
-[VkCube](https://github.com/KhronosGroup/Vulkan-Tools) running on Tyr soon.
-
-In any case, there is no power management and little error recovery. We will be
-working on that in the coming months.
+Our downstream branch (`tyr-dev`) provides a full, working prototype that can run GNOME, Weston, and full-screen 3D games like SuperTuxKart: see [Racing karts on a Rust GPU kernel driver](https://www.collabora.com/news-and-blog/news-and-events/racing-karts-on-a-rust-gpu-kernel-driver.html).
 
 ## Can I try it out?
 
@@ -65,7 +64,7 @@ replacing Panthor yet. A good candidate device is Radxa's
 A good starting point is to run our [IGT
 tests](https://gitlab.freedesktop.org/dwlsalmeida/igt-gpu-tools/-/tree/panthor?ref_type=heads).
 While only a subset of the tests pass on the upstream code for the reasons
-highlighted above, they should all pass if run on `tyr-next`.
+highlighted above, they should all pass if run on `tyr-dev`.
 
 Note that Mali GPUs are found in a vast array of devices, and that we will
 support more hardware as we progress in the implementation.
@@ -78,7 +77,8 @@ board](https://gitlab.freedesktop.org/panfrost/linux/-/issues/?label_name%5B%5D=
 We will be posting good starting tasks at a future point.
 
 To work on any given task, assign it to yourself and follow up with a merge
-request against `tyr-next`. Please also write the IGT tests needed to ensure that
-your code works.
+request against `tyr-for-upstream` (for patches targeting the upstream driver) or `tyr-dev` (for work in the downstream staging branch).
+
+Please also write the IGT tests needed to ensure that your code works.
 
 Happy hacking!