Re: port-macppc/59529: POWERMAC_G5 trap setting color palette

["Michael via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR port-macppc/59529; it has been noted by GNATS.

From: Michael <macallan1888%gmail.com@localhost>
To: Andreas Gustafsson <gson%gson.org@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: Re: port-macppc/59529: POWERMAC_G5 trap setting color palette
Date: Tue, 22 Jul 2025 21:28:16 -0400

 Hello,
 
 On Tue, 22 Jul 2025 22:10:40 +0300
 Andreas Gustafsson <gson%gson.org@localhost> wrote:
 
 > You wrote:
 > >  >   [    1.0000000] trap: kernel read DSI trap @ 0x8070200c by 0xff848714 (DSISR 0x40000000, err=14), lr 0xff87a524
 > >  >   [    1.0000000] Press a key to panic  
 > >  
 > >  I've seen this on newer, PCIe-based G5 models, we call OF_quiesce() to
 > >  shut down background tasks so we can have full control over the
 > >  hardware, but after that certain OF calls crash. IIRC rin@ committed a
 > >  workaround a while ago, no idea if it made it into 10.
 > >  
 > >  There are a few things to check:
 > >  - please try a -current kernel  
 > 
 > The problem also affects a kernel built from -current source date
 > 2025-06-05 11:30:23 Z.  I tried to build today's current but it
 > failed to build on my build host (that's PR 59543).
 
 Hmm, the workaround is 11,2-specific I think.
 
 > >  - try a -current kernel with gffb enabled. This will avoid the OF calls
 > >    and program palette registers directly  
 > 
 > The gffb driver is already enabled in the POWERMAC_G5 kernel, but it's
 > not attaching for me.
 > 
 > Please send me:
 > >  - dmesg output
 > >  - ofctl -p output
 > >  so I can fix that.  
 
 > Here:
 > 
 >   https://www.gson.org/netbsd/bugs/59529/dmesg.txt
 >   https://www.gson.org/netbsd/bugs/59529/ofctl-p.txt
 > 
 > The dmesg is from a kernel based on POWERMAC_G5 with some patches and
 > debug prints added, built from -current sources from 2025-06-05
 > 11:30:23 Z.
 
 So you do have an FX5200U. It should attach with a *very* recent -current.
 Also, plain old 7,3 - you should be able to run an SMP kernel with that as well.
 Got to look at my local tree - I have a 7,2 here, same graphics card
 and CPU, and genfb Just Work(tm)ed on mine.
 
 > >  envstat should list 6 or 7 fans and about 6 temperature sensors. If
 > >  yours shows less please be careful. The CPU has a huge heat sink so
 > >  overheating it will take a while under full load even with all fans
 > >  stopped ( which is unlikely to happen - OF will spin them up and if we
 > >  don't find the fans or temperature sensors we leave them alone ).  
 > 
 > guppy# envstat
 >                           Current  CritMax  WarnMax  WarnMin  CritMin  Unit
 > [adadc0]
 >       CPU A AD7417 AMB:    35.000                                      degC
 >       CPU A DIODE TEMP:    50.375                                      degC
 >         CPU A 12V CURR:     2.750                                         A
 >            CPU A VCORE:     1.438                                         V
 >        CPU A CORE CURR:    18.250                                         A
 
 That all looks good. The A-number you gave implied something different.
 Then again, maybe everymac.com got that one wrong.
 
 have fun
 Michael