Thanks, towo!
I see a "GPU crash dump saved to /sys/class/drm/card0/error":
# dmesg | egrep -i "fail|warn|error"
[ 0.903037] RAS: Correctable Errors collector initialized.
[ 1.094076] ACPI Warning: SystemIO range 0x0000000000001828-0x000000000000182F conflicts with OpRegion 0x0000000000001800-0x000000000000187F (\PMIO) (20201113/utaddress-204)
[ 1.094084] ACPI Warning: SystemIO range 0x0000000000001C40-0x0000000000001C4F conflicts with OpRegion 0x0000000000001C00-0x0000000000001FFF (\GPR) (20201113/utaddress-204)
[ 1.094088] ACPI Warning: SystemIO range 0x0000000000001C30-0x0000000000001C3F conflicts with OpRegion 0x0000000000001C00-0x0000000000001C3F (\GPRL) (20201113/utaddress-204)
[ 1.094091] ACPI Warning: SystemIO range 0x0000000000001C30-0x0000000000001C3F conflicts with OpRegion 0x0000000000001C00-0x0000000000001FFF (\GPR) (20201113/utaddress-204)
[ 1.094095] ACPI Warning: SystemIO range 0x0000000000001C00-0x0000000000001C2F conflicts with OpRegion 0x0000000000001C00-0x0000000000001C3F (\GPRL) (20201113/utaddress-204)
[ 1.094098] ACPI Warning: SystemIO range 0x0000000000001C00-0x0000000000001C2F conflicts with OpRegion 0x0000000000001C00-0x0000000000001FFF (\GPR) (20201113/utaddress-204)
[ 1.430960] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.SAT0.SPT4._GTF.DSSP], AE_NOT_FOUND (20201113/psargs-330)
[ 1.431069] ACPI Error: Aborting method \_SB.PCI0.SAT0.SPT4._GTF due to previous error (AE_NOT_FOUND) (20201113/psparse-529)
[ 1.432171] ACPI BIOS Error (bug): Could not resolve symbol [\_SB.PCI0.SAT0.SPT4._GTF.DSSP], AE_NOT_FOUND (20201113/psargs-330)
[ 1.432277] ACPI Error: Aborting method \_SB.PCI0.SAT0.SPT4._GTF due to previous error (AE_NOT_FOUND) (20201113/psparse-529)
[ 2.304862] usb 4-2: Set SEL for device-initiated U1 failed.
[ 2.304915] usb 4-2: Set SEL for device-initiated U2 failed.
[ 2.802129] EXT4-fs (sdb2): re-mounted. Opts: errors=remount-ro,discard. Quota mode: none.
[ 6392.975802] GPU crash dump saved to /sys/class/drm/card0/error
[23277.358171] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.358179] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.358184] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.359122] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.359132] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.359137] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.359960] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.359970] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.359974] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.360023] ldm_validate_partition_table(): Disk read failed.
[23277.360837] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.360843] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.360846] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.361650] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.361658] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.361661] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.362482] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.362487] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.362490] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.363273] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.363277] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.363279] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.364096] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.364101] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.364103] Buffer I/O error on dev sdj, logical block 0, async page read
[23277.364932] sd 9:0:0:2: [sdj] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
[23277.364938] blk_update_request: I/O error, dev sdj, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
[23277.364941] Buffer I/O error on dev sdj, logical block 0, async page read
[26796.166079] WARNING! power/level is deprecated; use power/control instead
Nothing else seems related....