** I have no early vt(4) driver: VT: init without driver. ** My WIP vt(4) fb driver fails to attach: terasic_mtl0: Failed to attach fbd device ** Later vt_upgrade gets called and panics: panic: vtbuf_fill_locked begin.tp_row 0 must be < screen height 0 cpuid = 0 KDB: enter: panic [ thread pid 0 tid 100000 ] Stopped at kdb_enter+0x8c: lui at,0x0 db> bt Tracing pid 0 tid 100000 td 0xffffffff80729c20 db_trace_thread+40 (?,?,?,?) ra ffffffff80117514 sp 98000000007c5ca0 sz 32 ffffffff80117388+18c (ff0000,?,ffffffff,?) ra ffffffff801165f0 sp 98000000007c5cc0 sz 64 ffffffff80116168+488 (?,?,?,?) ra ffffffff801168bc sp 98000000007c5d00 sz 224 db_command_loop+f4 (?,?,?,?) ra ffffffff8011a2c8 sp 98000000007c5de0 sz 32 ffffffff8011a120+1a8 (?,?,?,?) ra ffffffff802e3e10 sp 98000000007c5e00 sz 832 kdb_trap+1f0 (?,?,?,?) ra ffffffff80515bb0 sp 98000000007c6140 sz 64 trap+10d8 (?,?,?,?) ra ffffffff804ff34c sp 98000000007c6180 sz 320 MipsKernGenException+168 (0,0,80582490,aa) ra ffffffff802e3944 sp 98000000007c62c0 sz 448 kdb_enter+8c (?,?,?,?) ra ffffffff80293800 sp 98000000007c6480 sz 32 ffffffff80293550+2b0 (?,?,?,?) ra ffffffff80293930 sp 98000000007c64a0 sz 32 kassert_panic+c8 (?,0,0,107b3ac) ra ffffffff80186fd4 sp 98000000007c64c0 sz 128 vtbuf_fill_locked+54 (?,?,?,?) ra ffffffff80188ddc sp 98000000007c6540 sz 64 ffffffff80188dc8+14 (?,?,?,?) ra ffffffff802fc28c sp 98000000007c6580 sz 32 terminal_set_winsize_blank+1bc (?,?,?,?) ra ffffffff802fc2e0 sp 98000000007c65a0 sz 96 terminal_set_winsize+28 (?,?,?,?) ra ffffffff80189654 sp 98000000007c6600 sz 32 vt_upgrade+194 (?,?,?,?) ra ffffffff802231dc sp 98000000007c6620 sz 160 mi_startup+20c (?,?,?,?) ra ffffffff8010026c sp 98000000007c66c0 sz 32 _start+dc (?,?,?,?) ra 0 sp 98000000007c66e0 sz 0 pid 0 db> presumably vt_upgrade needs to detect the case that only the dummy driver exists, and do nothing
Created attachment 147965 [details] vtterm_cnprobe: Only recompute term size if screen size != 0 I see that there's no vt(4) driver built into RPI-B kernel configuration, therefore, the screen size is unknown (and set to 0). Could you please try the attached patch?
Oops, sorry, I added the patch to the wrong bug report... I meant to do this in 193981 :)
A commit references this bug: Author: emaste Date: Fri Oct 17 13:55:46 UTC 2014 New revision: 273219 URL: https://svnweb.freebsd.org/changeset/base/273219 Log: Do nothing in vt_upgrade if there is no vt driver Previously, if no drivers attached at boot we would panic with "vtbuf_fill_locked begin.tp_row 0 must be < screen height 0". PR: 192248 Reviewed by: ray MFC after: 3 days Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D954 Changes: head/sys/dev/vt/vt_core.c
A commit references this bug: Author: emaste Date: Mon Oct 20 01:01:55 UTC 2014 New revision: 273296 URL: https://svnweb.freebsd.org/changeset/base/273296 Log: MFC r273219: Do nothing in vt_upgrade if there is no vt driver Previously, if no drivers attached at boot we would panic with "vtbuf_fill_locked begin.tp_row 0 must be < screen height 0". PR: 192248 Changes: _U stable/10/ stable/10/sys/dev/vt/vt_core.c
A commit references this bug: Author: emaste Date: Mon Oct 20 03:17:49 UTC 2014 New revision: 273300 URL: https://svnweb.freebsd.org/changeset/base/273300 Log: MFS10 r273296 (r273219 in HEAD): Do nothing in vt_upgrade if there is no vt driver Previously, if no drivers attached at boot we would panic with "vtbuf_fill_locked begin.tp_row 0 must be < screen height 0". PR: 192248 Approved by: re Changes: _U releng/10.1/ releng/10.1/sys/dev/vt/vt_core.c