On 01/08/17 19:47, Laurent Pinchart wrote:
Hi Kieran,
On Tuesday 01 Aug 2017 18:35:48 Kieran Bingham wrote:
On 26/06/17 19:12, Laurent Pinchart wrote:
The VSP supports both header and headerless display lists. The latter is easier to use when the VSP feeds data directly to the DU in continuous mode, and the driver thus uses headerless display lists for DU operation and header display lists otherwise.
Headerless display lists are only available on WPF.0. This has never been an issue so far, as only WPF.0 is connected to the DU. However, on H3 ES2.0, the VSP-DL instance has both WPF.0 and WPF.1 connected to the DU. We thus can't use headerless display lists unconditionally for DU operation.
Would it be crazy to suggest we drop headerless display lists?
If we must support header display lists in continuous mode - Rather than having 2 cases for continuous modes to support (having to support headerless, on WPF.0, and header on WPF.1) if we just use your header loop trick - would that simplify our code maintenance?
(We can always remove headerless support later if you agree, this is more of an idea at the moment)
I had the exact same thought, but I believe we should wait a few kernel releases to see if the next code is stable before removing the old one. I have a debug patch that forces usage of header display lists unconditionally, and I'll try to develop a few additional stress-tests for that.
Sounds like a good plan.
-- Kieran