Rob Clark 6f1ccbf074 drm/vblank: Fix for drivers that do not drm_vblank_init()
This should fix a crash that was reported on ast (and possibly other
drivers which do not initialize vblank).

   fbcon: Taking over console
   Unable to handle kernel NULL pointer dereference at virtual address 0000000000000074
   Mem abort info:
     ESR = 0x0000000096000004
     EC = 0x25: DABT (current EL), IL = 32 bits
     SET = 0, FnV = 0
     EA = 0, S1PTW = 0
     FSC = 0x04: level 0 translation fault
   Data abort info:
     ISV = 0, ISS = 0x00000004
     CM = 0, WnR = 0
   user pgtable: 4k pages, 48-bit VAs, pgdp=0000080009d16000
   [0000000000000074] pgd=0000000000000000, p4d=0000000000000000
   Internal error: Oops: 0000000096000004 [#1] SMP
   Modules linked in: ip6table_nat tun nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables nfnetlink qrtr sunrpc binfmt_misc vfat fat xfs snd_usb_audio snd_hwdep snd_usbmidi_lib snd_seq snd_pcm snd_rawmidi snd_timer snd_seq_device snd soundcore joydev mc ipmi_ssif ipmi_devintf ipmi_msghandler arm_spe_pmu arm_cmn arm_dsu_pmu arm_dmc620_pmu cppc_cpufreq loop zram crct10dif_ce polyval_ce nvme polyval_generic ghash_ce sbsa_gwdt igb nvme_core ast nvme_common i2c_algo_bit xgene_hwmon gpio_dwapb scsi_dh_rdac scsi_dh_emc scsi_dh_alua ip6_tables ip_tables dm_multipath fuse
   CPU: 12 PID: 469 Comm: kworker/12:1 Not tainted 6.3.0-rc2-00008-gd39e48ca80c0 #1
   Hardware name: ADLINK AVA Developer Platform/AVA Developer Platform, BIOS TianoCore 2.04.100.07 (SYS: 2.06.20220308) 09/08/2022
   Workqueue: events fbcon_register_existing_fbs
   pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
   pc : drm_crtc_next_vblank_start+0x2c/0x98
   lr : drm_atomic_helper_wait_for_fences+0x90/0x240
   sp : ffff80000d583960
   x29: ffff80000d583960 x28: ffff07ff8fc187b0 x27: 0000000000000000
   x26: ffff07ff99c08c00 x25: 0000000000000038 x24: ffff07ff99c0c000
   x23: 0000000000000001 x22: 0000000000000038 x21: 0000000000000000
   x20: ffff07ff9640a280 x19: 0000000000000000 x18: ffffffffffffffff
   x17: 0000000000000000 x16: ffffb24d2eece1c0 x15: 0000003038303178
   x14: 3032393100000048 x13: 0000000000000000 x12: 0000000000000000
   x11: 0000000000000000 x10: 0000000000000000 x9 : ffffb24d2eeeaca0
   x8 : ffff80000d583628 x7 : 0000080077783000 x6 : 0000000000000000
   x5 : ffff80000d584000 x4 : ffff07ff99c0c000 x3 : 0000000000000130
   x2 : 0000000000000000 x1 : ffff80000d5839c0 x0 : ffff07ff99c0cc08
   Call trace:
    drm_crtc_next_vblank_start+0x2c/0x98
    drm_atomic_helper_wait_for_fences+0x90/0x240
    drm_atomic_helper_commit+0xb0/0x188
    drm_atomic_commit+0xb0/0xf0
    drm_client_modeset_commit_atomic+0x218/0x280
    drm_client_modeset_commit_locked+0x64/0x1a0
    drm_client_modeset_commit+0x38/0x68
    __drm_fb_helper_restore_fbdev_mode_unlocked+0xb0/0xf8
    drm_fb_helper_set_par+0x44/0x88
    fbcon_init+0x1e0/0x4a8
    visual_init+0xbc/0x118
    do_bind_con_driver.isra.0+0x194/0x3a0
    do_take_over_console+0x50/0x70
    do_fbcon_takeover+0x74/0xf8
    do_fb_registered+0x13c/0x158
    fbcon_register_existing_fbs+0x78/0xc0
    process_one_work+0x1ec/0x478
    worker_thread+0x74/0x418
    kthread+0xec/0x100
    ret_from_fork+0x10/0x20
   Code: f9400004 b9409013 f940a082 9ba30a73 (b9407662)
   ---[ end trace 0000000000000000 ]---

v2: Use drm_dev_has_vblank()

Reported-by: Nathan Chancellor <nathan@kernel.org>
Fixes: d39e48ca80 ("drm/atomic-helper: Set fence deadline for vblank")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20230403160314.1210533-1-robdclark@gmail.com
2023-04-04 22:38:03 +02:00
2022-09-28 09:02:20 +02:00
2023-03-29 16:00:23 +02:00
2023-03-26 14:40:20 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%