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

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

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

From: Andreas Gustafsson <gson%gson.org@localhost>
To: Michael <macallan1888%gmail.com@localhost>
Cc: gnats-bugs%netbsd.org@localhost, port-macppc-maintainer%netbsd.org@localhost
Subject: Re: port-macppc/59529: POWERMAC_G5 trap setting color palette
Date: Tue, 22 Jul 2025 22:10:40 +0300

 Hi Michael,
 
 Thank you for looking into this.
 
 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).
 
 >  - 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.
 
 >  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
 [adadc1]
       CPU B AD7417 AMB:    35.250                                      degC
       CPU B DIODE TEMP:    51.562                                      degC
         CPU B 12V CURR:     3.125                                         A
            CPU B VCORE:     1.438                                         V
        CPU B CORE CURR:    21.062                                         A
 [admtemp0]
               BACKSIDE:    42.000   85.000                     10.000  degC
            U3 HEATSINK:    47.875   85.250                     10.000  degC
 [admtemp1]
        MLB MAX6690 AMB:    33.000   85.000                    -55.000  degC
          MLB INLET AMB:    30.500   85.250                    -54.250  degC
 [fcu0]
              DRIVE BAY:      1000                                       RPM
           CPU A INTAKE:       357                                       RPM
          CPU A EXHAUST:       357                                       RPM
           CPU B INTAKE:       357                                       RPM
          CPU B EXHAUST:       357                                       RPM
               BACKSIDE:      1083                                       RPM
                   SLOT:      1089                                       RPM
       Overtemp* Signal:      TRUE
   Air Deflector Signal:      TRUE
 [lmtemp0]
              DRIVE BAY:    28.000   80.000                             degC
 [obiofan0]
             PWR SUPPLY:       N/A
 
 -- 
 Andreas Gustafsson, gson%gson.org@localhost