This patch avoid the warning in vkms_get_vblank_timestamp when vblanks aren't enabled. When running igt test kms_cursor_crc just after vkms module, the warning raised like below. Initial value of vblank time is zero and hrtimer.node.expires is also zero if vblank aren't enabled before. vkms module isn't real hardware but just virtual hardware module. so vkms can't generate a resonable timestamp when hrtimer is off. it's best to grab the current time.

[106444.464503] [IGT] kms_cursor_crc: starting subtest pipe-A-cursor-size-change [106444.471475] WARNING: CPU: 0 PID: 10109 at /home/realwakka/git/linux/drivers/gpu/drm/vkms//vkms_crtc.c:91 vkms_get_vblank_timestamp+0x42/0x50 [vkms] [106444.471511] CPU: 0 PID: 10109 Comm: kms_cursor_crc Tainted: G W OE 5.9.0-rc1+ #6 [106444.471514] RIP: 0010:vkms_get_vblank_timestamp+0x42/0x50 [vkms] [106444.471528] Call Trace: [106444.471551] drm_get_last_vbltimestamp+0xb9/0xd0 [drm] [106444.471566] drm_reset_vblank_timestamp+0x63/0xe0 [drm] [106444.471579] drm_crtc_vblank_on+0x85/0x150 [drm] [106444.471582] vkms_crtc_atomic_enable+0xe/0x10 [vkms] [106444.471592] drm_atomic_helper_commit_modeset_enables+0x1db/0x230 [drm_kms_helper] [106444.471594] vkms_atomic_commit_tail+0x38/0xc0 [vkms] [106444.471601] commit_tail+0x97/0x130 [drm_kms_helper] [106444.471608] drm_atomic_helper_commit+0x117/0x140 [drm_kms_helper] [106444.471622] drm_atomic_commit+0x4a/0x50 [drm] [106444.471629] drm_atomic_helper_set_config+0x63/0xb0 [drm_kms_helper] [106444.471642] drm_mode_setcrtc+0x1d9/0x7b0 [drm] [106444.471654] ? drm_mode_getcrtc+0x1a0/0x1a0 [drm] [106444.471666] drm_ioctl_kernel+0xb6/0x100 [drm] [106444.471677] drm_ioctl+0x3ad/0x470 [drm] [106444.471688] ? drm_mode_getcrtc+0x1a0/0x1a0 [drm] [106444.471692] ? tomoyo_file_ioctl+0x19/0x20 [106444.471694] __x64_sys_ioctl+0x96/0xd0 [106444.471697] do_syscall_64+0x37/0x80 [106444.471699] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Cc: Daniel Vetter daniel@ffwll.ch Cc: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com Cc: Haneen Mohammed hamohammed.sa@gmail.com Cc: Melissa Wen melissa.srw@gmail.com

Signed-off-by: Sidong Yang realwakka@gmail.com

---

v3: - add cc.

v2: - modify commit message to make it a bit easier to understand.

--- drivers/gpu/drm/vkms/vkms_crtc.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c index ac85e17428f8..09c012d54d58 100644 --- a/drivers/gpu/drm/vkms/vkms_crtc.c +++ b/drivers/gpu/drm/vkms/vkms_crtc.c @@ -86,6 +86,11 @@ static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc, struct vkms_output *output = &vkmsdev->output; struct drm_vblank_crtc *vblank = &dev->vblank[pipe];

+ if (!READ_ONCE(vblank->enabled)) { + *vblank_time = ktime_get(); + return true; + } + *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);

if (WARN_ON(*vblank_time == vblank->time))