[PATCH 2/2] drm/amdgpu: Fix dead lock issue for vblank
Deng, Emily
Emily.Deng at amd.com
Fri Sep 18 08:29:30 UTC 2020
Thanks, will double check.
Best wishes
Emily Deng
>-----Original Message-----
>From: Zhang, Hawking <Hawking.Zhang at amd.com>
>Sent: Friday, September 18, 2020 4:20 PM
>To: Deng, Emily <Emily.Deng at amd.com>; amd-gfx at lists.freedesktop.org
>Cc: Deng, Emily <Emily.Deng at amd.com>
>Subject: RE: [PATCH 2/2] drm/amdgpu: Fix dead lock issue for vblank
>
>[AMD Public Use]
>
>+ spin_lock_irqsave(&adev->ddev->event_lock, flags);
>
>Are you sure you used the latest code base? I think recently we already switch
>to adev_to_drm(adev).
>
>Could you please double check?
>
>Regards,
>Hawking
>
>-----Original Message-----
>From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
>Emily.Deng
>Sent: Friday, September 18, 2020 11:27
>To: amd-gfx at lists.freedesktop.org
>Cc: Deng, Emily <Emily.Deng at amd.com>
>Subject: [PATCH 2/2] drm/amdgpu: Fix dead lock issue for vblank
>
>Always start vblank timer, but only calls vblank function when vblank is enabled.
>
>This is used to fix the dead lock issue.
>When drm_crtc_vblank_off want to disable vblank, it first get event_lock, and
>then call hrtimer_cancel, but hrtimer_cancel want to wait timer handler
>function finished.
>Timer handler also want to aquire event_lock in drm_handle_vblank.
>
>Signed-off-by: Emily.Deng <Emily.Deng at amd.com>
>Change-Id: I7d3cfb1202cd030fdcdec3e7483fcc4c9fa8db70
>---
> drivers/gpu/drm/amd/amdgpu/dce_virtual.c | 155 +++++++++++------------
> 1 file changed, 77 insertions(+), 78 deletions(-)
>
>diff --git a/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
>b/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
>index cc93577dee03..8c02ab74c1de 100644
>--- a/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
>+++ b/drivers/gpu/drm/amd/amdgpu/dce_virtual.c
>@@ -226,6 +226,74 @@ static const struct drm_crtc_helper_funcs
>dce_virtual_crtc_helper_funcs = {
> .get_scanout_position = amdgpu_crtc_get_scanout_position, };
>
>+static int dce_virtual_pageflip(struct amdgpu_device *adev,
>+ unsigned crtc_id)
>+{
>+ unsigned long flags;
>+ struct amdgpu_crtc *amdgpu_crtc;
>+ struct amdgpu_flip_work *works;
>+
>+ amdgpu_crtc = adev->mode_info.crtcs[crtc_id];
>+
>+ if (crtc_id >= adev->mode_info.num_crtc) {
>+ DRM_ERROR("invalid pageflip crtc %d\n", crtc_id);
>+ return -EINVAL;
>+ }
>+
>+ /* IRQ could occur when in initial stage */
>+ if (amdgpu_crtc == NULL)
>+ return 0;
>+
>+ spin_lock_irqsave(&adev->ddev->event_lock, flags);
>+ works = amdgpu_crtc->pflip_works;
>+ if (amdgpu_crtc->pflip_status != AMDGPU_FLIP_SUBMITTED) {
>+ DRM_DEBUG_DRIVER("amdgpu_crtc->pflip_status = %d != "
>+ "AMDGPU_FLIP_SUBMITTED(%d)\n",
>+ amdgpu_crtc->pflip_status,
>+ AMDGPU_FLIP_SUBMITTED);
>+ spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
>+ return 0;
>+ }
>+
>+ /* page flip completed. clean up */
>+ amdgpu_crtc->pflip_status = AMDGPU_FLIP_NONE;
>+ amdgpu_crtc->pflip_works = NULL;
>+
>+ /* wakeup usersapce */
>+ if (works->event)
>+ drm_crtc_send_vblank_event(&amdgpu_crtc->base, works-
>>event);
>+
>+ spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
>+
>+ drm_crtc_vblank_put(&amdgpu_crtc->base);
>+ amdgpu_bo_unref(&works->old_abo);
>+ kfree(works->shared);
>+ kfree(works);
>+
>+ return 0;
>+}
>+
>+static enum hrtimer_restart dce_virtual_vblank_timer_handle(struct
>+hrtimer *vblank_timer) {
>+ struct amdgpu_crtc *amdgpu_crtc = container_of(vblank_timer,
>+ struct amdgpu_crtc,
>vblank_timer);
>+ struct drm_device *ddev = amdgpu_crtc->base.dev;
>+ struct amdgpu_device *adev = ddev->dev_private;
>+ struct amdgpu_irq_src *source = adev-
>>irq.client[AMDGPU_IRQ_CLIENTID_LEGACY].sources
>+ [VISLANDS30_IV_SRCID_SMU_DISP_TIMER2_TRIGGER];
>+ int irq_type = amdgpu_display_crtc_idx_to_irq_type(adev,
>+ amdgpu_crtc->crtc_id);
>+
>+ if (amdgpu_irq_enabled(adev, source, irq_type)) {
>+ drm_handle_vblank(ddev, amdgpu_crtc->crtc_id);
>+ dce_virtual_pageflip(adev, amdgpu_crtc->crtc_id);
>+ }
>+ hrtimer_start(vblank_timer, ktime_set(0,
>DCE_VIRTUAL_VBLANK_PERIOD),
>+ HRTIMER_MODE_REL);
>+
>+ return HRTIMER_NORESTART;
>+}
>+
> static int dce_virtual_crtc_init(struct amdgpu_device *adev, int index) {
> struct amdgpu_crtc *amdgpu_crtc;
>@@ -247,6 +315,14 @@ static int dce_virtual_crtc_init(struct amdgpu_device
>*adev, int index)
> amdgpu_crtc->vsync_timer_enabled = AMDGPU_IRQ_STATE_DISABLE;
> drm_crtc_helper_add(&amdgpu_crtc->base,
>&dce_virtual_crtc_helper_funcs);
>
>+ hrtimer_init(&amdgpu_crtc->vblank_timer,
>+ CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>+ hrtimer_set_expires(&amdgpu_crtc->vblank_timer,
>+ ktime_set(0, DCE_VIRTUAL_VBLANK_PERIOD));
>+ amdgpu_crtc->vblank_timer.function =
>+ dce_virtual_vblank_timer_handle;
>+ hrtimer_start(&amdgpu_crtc->vblank_timer,
>+ ktime_set(0, DCE_VIRTUAL_VBLANK_PERIOD),
>HRTIMER_MODE_REL);
> return 0;
> }
>
>@@ -476,7 +552,7 @@ static int dce_virtual_hw_fini(void *handle)
>
> for (i = 0; i<adev->mode_info.num_crtc; i++)
> if (adev->mode_info.crtcs[i])
>- dce_virtual_set_crtc_vblank_interrupt_state(adev, i,
>AMDGPU_IRQ_STATE_DISABLE);
>+ hrtimer_cancel(&adev->mode_info.crtcs[i]-
>>vblank_timer);
>
> return 0;
> }
>@@ -645,68 +721,6 @@ static void dce_virtual_set_display_funcs(struct
>amdgpu_device *adev)
> adev->mode_info.funcs = &dce_virtual_display_funcs; }
>
>-static int dce_virtual_pageflip(struct amdgpu_device *adev,
>- unsigned crtc_id)
>-{
>- unsigned long flags;
>- struct amdgpu_crtc *amdgpu_crtc;
>- struct amdgpu_flip_work *works;
>-
>- amdgpu_crtc = adev->mode_info.crtcs[crtc_id];
>-
>- if (crtc_id >= adev->mode_info.num_crtc) {
>- DRM_ERROR("invalid pageflip crtc %d\n", crtc_id);
>- return -EINVAL;
>- }
>-
>- /* IRQ could occur when in initial stage */
>- if (amdgpu_crtc == NULL)
>- return 0;
>-
>- spin_lock_irqsave(&adev_to_drm(adev)->event_lock, flags);
>- works = amdgpu_crtc->pflip_works;
>- if (amdgpu_crtc->pflip_status != AMDGPU_FLIP_SUBMITTED) {
>- DRM_DEBUG_DRIVER("amdgpu_crtc->pflip_status = %d != "
>- "AMDGPU_FLIP_SUBMITTED(%d)\n",
>- amdgpu_crtc->pflip_status,
>- AMDGPU_FLIP_SUBMITTED);
>- spin_unlock_irqrestore(&adev_to_drm(adev)->event_lock,
>flags);
>- return 0;
>- }
>-
>- /* page flip completed. clean up */
>- amdgpu_crtc->pflip_status = AMDGPU_FLIP_NONE;
>- amdgpu_crtc->pflip_works = NULL;
>-
>- /* wakeup usersapce */
>- if (works->event)
>- drm_crtc_send_vblank_event(&amdgpu_crtc->base, works-
>>event);
>-
>- spin_unlock_irqrestore(&adev_to_drm(adev)->event_lock, flags);
>-
>- drm_crtc_vblank_put(&amdgpu_crtc->base);
>- amdgpu_bo_unref(&works->old_abo);
>- kfree(works->shared);
>- kfree(works);
>-
>- return 0;
>-}
>-
>-static enum hrtimer_restart dce_virtual_vblank_timer_handle(struct hrtimer
>*vblank_timer) -{
>- struct amdgpu_crtc *amdgpu_crtc = container_of(vblank_timer,
>- struct amdgpu_crtc,
>vblank_timer);
>- struct drm_device *ddev = amdgpu_crtc->base.dev;
>- struct amdgpu_device *adev = drm_to_adev(ddev);
>-
>- drm_handle_vblank(ddev, amdgpu_crtc->crtc_id);
>- dce_virtual_pageflip(adev, amdgpu_crtc->crtc_id);
>- hrtimer_start(vblank_timer, DCE_VIRTUAL_VBLANK_PERIOD,
>- HRTIMER_MODE_REL);
>-
>- return HRTIMER_NORESTART;
>-}
>-
> static void dce_virtual_set_crtc_vblank_interrupt_state(struct amdgpu_device
>*adev,
> int crtc,
> enum
>amdgpu_interrupt_state state) @@ -716,21 +730,6 @@ static void
>dce_virtual_set_crtc_vblank_interrupt_state(struct amdgpu_device *ad
> return;
> }
>
>- if (state && !adev->mode_info.crtcs[crtc]->vsync_timer_enabled) {
>- DRM_DEBUG("Enable software vsync timer\n");
>- hrtimer_init(&adev->mode_info.crtcs[crtc]->vblank_timer,
>- CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>- hrtimer_set_expires(&adev->mode_info.crtcs[crtc]-
>>vblank_timer,
>- DCE_VIRTUAL_VBLANK_PERIOD);
>- adev->mode_info.crtcs[crtc]->vblank_timer.function =
>- dce_virtual_vblank_timer_handle;
>- hrtimer_start(&adev->mode_info.crtcs[crtc]->vblank_timer,
>- DCE_VIRTUAL_VBLANK_PERIOD,
>HRTIMER_MODE_REL);
>- } else if (!state && adev->mode_info.crtcs[crtc]->vsync_timer_enabled)
>{
>- DRM_DEBUG("Disable software vsync timer\n");
>- hrtimer_cancel(&adev->mode_info.crtcs[crtc]->vblank_timer);
>- }
>-
> adev->mode_info.crtcs[crtc]->vsync_timer_enabled = state;
> DRM_DEBUG("[FM]set crtc %d vblank interrupt state %d\n", crtc,
>state); }
>--
>2.25.1
>
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