Hi Tomi, On 10/3/24 10:53, Sean Anderson wrote: > On 10/2/24 10:50, Tomi Valkeinen wrote: >> Hi, >> >> On 01/10/2024 21:31, Sean Anderson wrote: >>> On 8/9/24 15:35, Sean Anderson wrote: >>>> This series cleans up the zyqnmp_dp IRQ and locking situation. Once >>>> that's done, it adds debugfs support. The intent is to enable compliance >>>> testing or to help debug signal-integrity issues. >> >> I think the patches 1-7 look fine, and I think I can pick those already to drm-misc if you're ok with that. >> >> I'm a bit unsure about patch 8, probably mainly because I don't have experience with the compliance testing. >> >> How have you tested this? With some DP analyzer/tester, I presume? > > For my test setup I used an oscilloscope hooked up to the displayport > output using a fixture that broke the signals out to SMA. Since the > oscilloscope cannot emulate a sink, I first had the output connected to > a monitor. Then I disabled HPD and reconnected the output to my fixture. > This process is described in more detail in the documentation. > >> I think none of this (patch 8) is needed by almost anybody. > > Well, I found it very useful for debugging a signal integrity issue I > was having. Once I could have a look at the signals it was very clear > what the problem was. > >> Even among zynqmp_dp developers I assume it's very rare to have the >> hardware for this. I wonder if it would make sense to have the debugfs >> and related code behind a compile option (which would be nice as the >> code wouldn't even compiled in), or maybe a module parameter (which >> would be nice as then "anyone" can easily enable it for compliance >> testing). What do you think? > > Other drivers with these features just enabled it unconditionally, so I > didn't bother with any special config. > >> I also somehow recall that there was some discussion earlier about >> how/if other drivers support compliance testing. But I can't find the >> discussion. Do you remember if there was such discussion, and what was >> the conclusion? With a quick look, everything in the debugfs looks >> generic, not xilinx specific. > > The last it got discussed was back in [1], but I never got any further > response. I agree that some of this is generic, and could probably be > reworked into some internal helpers. But I don't have the bandwidth at > the moment to do that work. > > --Sean > > [1] http://lore.kernel.org/dri-devel/cda22b0c-8d7c-4ce2-9a7c-3b5ab540fa1f@xxxxxxxxx Does this all make sense to you? At the moment I don't believe I have any changes I need to resend for (although this series is archived in patchwork [1] for some reason). --Sean [1] https://patchwork.kernel.org/project/dri-devel/list/?series=878338&archive=both
