On Fri, Nov 01, 2013 at 03:13:17PM +0000, Lin, Mengdong wrote: > > Maybe we could use the port CRC stuff to make sure that audio is actually > > working ... > > Would you please clarify what's port CRC stuff? The hw has a bunch of CRC (checksum) functions. We've just enabled it at the pipe level, and it's extremely useful to test whether e.g. the cursor is displaying properly or whether it's not shown at all. We've had a few bugs where the cursor was disabled but shouldnt have been. For an example of such a testcase see i-g-t/tests/kms_cursor_crc.c. This is all really new, so still in flux. Now the hardware also has checksum support for each port, and afaik that includes the audio stream. Iirc never platforms even have special CRCs for the individual audio streams. My idea for a testcase would be to expose these port CRCs. Then check that the CRC is stable for each display frame while no audio is playing, and that it changes (and that the right port starts to change) once we play an audio stream. We can't test sync issues with that, but routing issues (which seems to have been the issue here, and I've also seen a few patches for routing issues in the past) should be testable. And with an automated testcase we can ensure that no regression creps in. The other upside of an automated test like that is that it should be easy to test all port combinations. That's more important for desktop platforms where we have 3 HDMI/DP ports. Anyway I've just thought I'll bring this up as an idea to look into for the next hw enabling project. It was a bit an effort to enable pipe CRCs for display testing, but I think long-term it will definitely be worth it. So maybe poke the audio hw engineers/validation ppl a bit and inquire whether/how exactly they use this? We've had a display micro architect help us out a bit on the display side. Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
