00:05 karolherbst: I am sure I am messing this up
00:07 karolherbst: there is pcibios_resource_to_bus
00:09 karolherbst: heh...
00:10 karolherbst: nvm
00:10 karolherbst: seems like there are GPUs where reading from the option ROM directly returns only garbage
00:10 karolherbst: now I am confused
08:25 hell__: hmmm
08:26 hell__: karolherbst: apparently this can happen if shadow is enabled: https://envytools.readthedocs.io/en/latest/hw/bus/bars.html#bar6-pci-rom-aperture
08:26 hell__: I don't know what it means
16:13 karolherbst: hell__: ohhhh
16:13 karolherbst: that would/could explain so much
16:14 karolherbst: but PROM reads don't return garbage.. mhh
16:14 karolherbst: maybe that's different on newer chips
16:17 karolherbst: okay.. that shadow reg is at 0x50
16:18 karolherbst: hell__: bingo
16:19 karolherbst: so I am able to read out the vbios from the address stored in 0x30
16:19 karolherbst: mhhh.. let me write some code :D
16:20 karolherbst: although I am curious if whacking 0x80 is enough to make PROM work for johns
16:21 karolherbst: uhm.. 0x50
21:58 karolherbst: johns, hell__: yeah.. okay, I think we should be able to fix this issue inside nouveau. "Some" GPUs are just different as it seems. Still would like a bit more info in order to figure out how the workaround should look like for real
21:59 karolherbst: I prefer making PROM work and that PCI config + 0x50 bit _might_ be the key to that, but some of my GPUs don't care about that value, some do, but PROM was always working contrary to fetching the PCI ROM from the non shadowed address
22:01 hell__: hrm
22:02 karolherbst: ohh.. maybe it's different on very old GPUs, but now I am too lazy to check
23:24 Mangix: alright. time to read nouveau code
23:30 Mangix: ugh needs patching. 225 and 297MHz are way too low
23:34 Mangix: And the 340MHz limit seems to be a DRM limitation...sigh
23:34 karolherbst: well. can't go higher than 340 without HDMI 2.0
23:34 Mangix: of course you can
23:35 Mangix: I'm specifically talking about dual link DVI
23:36 karolherbst: wasn't 165 MHz the max DVI allows?
23:36 Mangix: that's for single link. In any case, that's just the spec
23:36 Mangix: in practice you can go higher
23:36 karolherbst: yeah well...
23:36 karolherbst: not if the hw doesn't
23:36 Mangix: https://www.monitortests.com/ <-- has driver patchers for Windows to avoid driver limitations
23:37 Mangix: This current monitor can do 2560x1440@110Hz
23:37 Mangix: but not without driver patching
23:37 karolherbst: right...
23:38 karolherbst: well... going out of spec could lead to weird side effects, but if one writes the code to support all of that, why not
23:38 Mangix: most of the issue is making sense of the current code :)
23:38 karolherbst: but isn't 2560x1440@110 quite close to the 2x 165MHz limit?
23:39 Mangix: karolherbst: it's over 410MHz pixel clock IIRC. I'd have to check
23:39 karolherbst: mhh
23:39 Mangix: definitely over 404
23:39 Mangix: 404 is 102Hz IIRC
23:40 karolherbst: the hw can do 300MHz at most through HDMI anyway, so dual link should be sufficient
23:40 karolherbst: I am just mostly wondering why displays allow that kind of stuff because that's obviously out of spec
23:41 Mangix: depends on the display really
23:41 karolherbst: well.. out of spec is out of spec
23:41 Mangix: My more recent BenQ refuses to go above 600MHz
23:41 Mangix: this QX2710 doesn't care
23:41 karolherbst: yep, that's the limit for HDMI 2.0
23:41 Mangix: funny you say that
23:42 Mangix: that's over DisplayPort
23:42 karolherbst: heh
23:42 karolherbst: let's see what display ports limit is
23:42 Mangix: Maybe internally it does an HDMI 2.0 > DP conversion
23:42 Mangix: 640 I think
23:42 karolherbst: might be
23:42 Mangix: https://www.monitortests.com/blog/common-pixel-clock-limits/
23:42 karolherbst: but could also be that the display simply converts DP to HDMI
23:43 Mangix: right
23:43 Mangix: oh wow
23:43 Mangix: 810MHz
23:44 Mangix: Hmmm that poses more questions than answers
23:44 Mangix: oh that's funny "Technically no limit defined by the DVI specification, but often limited to 330 MHz." <-- I thought this was a bug in the amdgpu driver
23:47 Mangix: hmmm looks like nouveau has a 330MHz limit for dual link dvi. Unless I'm reading it wrong.