From 05ca530268a9d0ab3547e7b288635e35990a77c4 Mon Sep 17 00:00:00 2001
From: Sidong Yang <realwakka@gmail.com>
Date: Fri, 28 Aug 2020 12:45:53 +0000
Subject: [PATCH] drm/vkms: avoid warning in vkms_get_vblank_timestamp
Git-commit: 05ca530268a9d0ab3547e7b288635e35990a77c4
Patch-mainline: v5.10-rc1
References: git-fixes
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
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>
Reviewed-by: Melissa Wen <melissa.srw@gmail.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200828124553.2178-1-realwakka@gmail.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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))
--
2.26.2