• Rob Clark's avatar
    drm/vblank: Fix for drivers that do not drm_vblank_init() · 6f1ccbf0
    Rob Clark authored
    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-gd39e48ca #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: default avatarNathan Chancellor <nathan@kernel.org>
    Fixes: d39e48ca ("drm/atomic-helper: Set fence deadline for vblank")
    Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
    Reviewed-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
    Tested-by: default avatarNathan Chancellor <nathan@kernel.org>
    Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
    Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230403160314.1210533-1-robdclark@gmail.com
    6f1ccbf0
drm_vblank.c 68.9 KB