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Graphics Card install
meklort:
--- Quote from: madscientist159 on December 03, 2019, 11:28:19 pm ---
--- Code: ---No outputs definitely connected, trying again...
--- End code ---
This isn't a POWER problem, this is an AMD GPU driver / hardware problem. We're going to need a lot more info including the monitor model etc. -- last time I saw this you had to flip DisplayCore on or off, but Navi may require DisplayCore to operate at all. If the latter is the case, you'll need to contact AMD support to get the driver fixes.
--- End quote ---
Yes, agreed, it's a problem with the driver (again, I'm assuming it's only a driver issues on ppc64le and not x86_64, but that's only an assumption) as it's not even detecting that there's anything that a monitor could be plugged into.
Note that I did test with amdgpu.dc=1 and amdgpu.dc=0 and there was no change, however my understanding is that navi only works it enabled like you said
Do you know the best way to contact AMD about this? I can run through the appropriate channels to try to get the support improved.
MauryG5:
no I personally no, since you are more competent in the matter, see if you can understand how to communicate these problems to them. What I would like to understand instead is, AMD only develops for X86 as a rule, how do you request drivers for Power? Also on the site there are only those for X86 ... Maybe they release the source code because they are open source and then someone then develops the drivers for Power or what?
MauryG5:
but instead I was also thinking about the procedure that Raptor published on Wiki but I didn't understand. This is the configuration of the Xorg.conf file, the procedure that allows you to activate the graphics card via Xorg you can post it in detail as you did with that of the petitboot? I would like to understand if it is possible through that to activate the GPU ...
madscientist159:
--- Quote from: meklort on December 04, 2019, 06:19:14 am ---
--- Quote from: madscientist159 on December 03, 2019, 11:28:19 pm ---
--- Code: ---No outputs definitely connected, trying again...
--- End code ---
This isn't a POWER problem, this is an AMD GPU driver / hardware problem. We're going to need a lot more info including the monitor model etc. -- last time I saw this you had to flip DisplayCore on or off, but Navi may require DisplayCore to operate at all. If the latter is the case, you'll need to contact AMD support to get the driver fixes.
--- End quote ---
Yes, agreed, it's a problem with the driver (again, I'm assuming it's only a driver issues on ppc64le and not x86_64, but that's only an assumption) as it's not even detecting that there's anything that a monitor could be plugged into.
Note that I did test with amdgpu.dc=1 and amdgpu.dc=0 and there was no change, however my understanding is that navi only works it enabled like you said
Do you know the best way to contact AMD about this? I can run through the appropriate channels to try to get the support improved.
--- End quote ---
To be honest I'd be very, very surprised if there was a ppc64le specific bug in the AMD display detection. That code is all straight C, and the bit count and endianness both match x86 exactly.
Probably the first step is for anyone seeing this problem on Navi on POWER to try the exact same kernel version on some old / borrowed x86 system with the same card and monitor. If that also shows the same problem, at least when reported to the kernel bugtracker the devs won't immediately assume it's a POWER bug. :)
meklort:
This issue is due to Navi display support only being enabled for X86.
See here: https://github.com/torvalds/linux/blob/v5.4/drivers/gpu/drm/amd/display/Kconfig#L23
And here: https://github.com/torvalds/linux/blob/v5.4/drivers/gpu/drm/amd/display/dc/calcs/Makefile#L27
And here: https://github.com/torvalds/linux/blob/v5.4/drivers/gpu/drm/amd/display/dc/calcs/dcn_calcs.c#L629
Basically, before this will work the following needs to happen:
Either the DC code needs to be modified to use integer math instead of floating point math or
* The kernel_fpu_begin / kernel_fpu_end APIs need to be added for POWER (currently only supported on x86 and s390)
* The KConfig files need to be updated to enable POWER in addition to X86
* The Makefiles need to be modified to not assume x86 (and sse / sse2)
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