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
