Hi Maxime,
On 07/09/2026 16:23, Maxime Ripard wrote:
Hi,
Here's a series that implement what i915 calls "fastboot", ie,
initializing the initial KMS state from the hardware state at boot, to
skip the first modeset if the firmware already set up the display.
This series creates the infrastructure in KMS to create that state by
relying on driver specific hooks. It also implements some infrastructure
to check during non-blocking commits that the readout helpers work
properly by reading out the state that was just committed and comparing
it to what was supposed to be committed.
This relies on another set of driver hooks to compare the entities
states, with helpers providing the default implementation.
It then implements the readout support in the TIDSS driver, and was
tested with the SK-AM62 board. This board in particular is pretty
interesting, since it relies on an DPI to HDMI bridge, and uses the
drm_bridge_connector infrastructure.
So the readout works with the current state of the art on embedded-ish
platforms.
Unlike the earlier RFCs, it now works fine: the state is picked up
properly, doesn't trigger a modeset if what was programmed is the one
the first modeset tries to pick as well, will switch properly if it
isn't, etc.
Let me know what you think,
Thanks for working on this. I tested the earlier versions sometime in
the beginning of the year, and finally found time to look at this again.
I'm testing on AM62-SK, with HDMI and OLDI (separately and together,
u-boot enabled and not enabled), and I've found multiple issues.
Some of the issues are quite obvious, like OLDI bridge and panel_bridge
missing the SRO support. Some are related to using tidss with multiple
displays (or just one, but the "wrong" one enabled in the u-boot), but
the current code expects just the HDMI to be in use. And I think there
are a few on the framework side too.
So far I've been just hacking through the issues, so I don't have
anything to share. I just wanted to tell I'm working on this, and
hopefully late this week or next week I can share my findings, or
perhaps even proper patches.
But I can already see that it's (almost) working, so good work =).
Tomi
