Date: Tue, 25 Jun 2019 17:58:02 +0200 From: Milan Obuch <freebsd-arm@dino.sk> To: Emmanuel Vadot <manu@bidouilliste.com> Cc: freebsd-arm@freebsd.org Subject: Re: Pine64+ HDMI output note Message-ID: <20190625175802.50c8c3e0@zeta.dino.sk> In-Reply-To: <20190625083249.8802d2fb4723a8c7c79bf953@bidouilliste.com> References: <20190616093439.5bcbe869@zeta.dino.sk> <20190625083249.8802d2fb4723a8c7c79bf953@bidouilliste.com>
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On Tue, 25 Jun 2019 08:32:49 +0200 Emmanuel Vadot <manu@bidouilliste.com> wrote: > On Sun, 16 Jun 2019 09:34:39 +0200 > Milan Obuch <freebsd-arm@dino.sk> wrote: [ snip ] > > which makes me think, together with presence of getty processes > > attached to /dev/ttyvN devices, that all what's missing is just > > physical video output signal, and this is most probably caused by > > output buffer being shut down. So I googled a bit and found a hint, > > tried it - I put line > > > > hw.regulator.disable_unused=0 > > > > into /boot/loader.conf file and it works. I think it just uses HDMI > > output engine configured by u-boot instead of configuring it > > itself, as we have no driver for hdmi and hdmi-phy devices on A64 > > SoCs. > > With this you are using efifb. > The reason for the tunable is that since there is no node in the dtb > related to efifb the kernel will shutdown every regulator that isn't > referenced, this is 1) to save power 2) to do the same thing as the > Linux kernel as at one point I commited some bad DTS into Linux where > almost every regulator got shutdown after a while. > Thanks for explanation. > > Maybe this is just as simple as adding appropriate compatible string > > into arm/allwinner/a10_hdmi.c file, but I do not know if A20 and A64 > > cores are compatible in this area... and workaround found is just OK > > for me. > > No, A64 uses the version 2 of the Allwinner display engine, I have a > DRM driver working for it (but still have some work to do on it). > https://github.com/evadot/freebsd/tree/drm_aw_de2 > OK. Maybe I'll try it, but I have no immediate need for it... good to know I can expect it in some future, far or near :) > > Next step would be to try X on Pine64+... Any hint on this? I am > > going to try scfb video driver for this, as noted on > > FreeBSD/arm/Allwinner wiki page. As for this wiki page - maybe it > > could be updated in 'supported devices' table, in column A64 - I > > think framebuffer works and HDMI video too, kind of, leaving it in > > pre-initialised state with above mentioned workaround. > > SCFB driver will work correctly with efifb. > Confirmed. I checked it on my Pine64-LTS acquired recently as well. Now I am trying various ports/applications on it when time permits... Regards, Milan
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