[PATCH xf86-video-amdgpu 3/4] Defer vblank event handling while waiting for a pending flip
Michel Dänzer
michel at daenzer.net
Tue Jul 24 17:16:55 UTC 2018
From: Michel Dänzer <michel.daenzer at amd.com>
This is a more robust way to prevent hangs due to nested calls to
drmHandleEvent.
Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
src/amdgpu_drm_queue.c | 124 +++++++++++++++++++++++++++++++++++++----
src/amdgpu_drm_queue.h | 1 +
src/drmmode_display.c | 18 ++++--
src/drmmode_display.h | 4 ++
4 files changed, 131 insertions(+), 16 deletions(-)
diff --git a/src/amdgpu_drm_queue.c b/src/amdgpu_drm_queue.c
index 9c0166147..d4353e703 100644
--- a/src/amdgpu_drm_queue.c
+++ b/src/amdgpu_drm_queue.c
@@ -40,6 +40,7 @@
struct amdgpu_drm_queue_entry {
struct xorg_list list;
+ uint64_t usec;
uint64_t id;
uintptr_t seq;
void *data;
@@ -47,13 +48,27 @@ struct amdgpu_drm_queue_entry {
xf86CrtcPtr crtc;
amdgpu_drm_handler_proc handler;
amdgpu_drm_abort_proc abort;
+ unsigned int frame;
};
static int amdgpu_drm_queue_refcnt;
static struct xorg_list amdgpu_drm_queue;
+static struct xorg_list amdgpu_drm_queue_deferred;
static uintptr_t amdgpu_drm_queue_seq;
+static void
+amdgpu_drm_queue_handle_one(struct amdgpu_drm_queue_entry *e, unsigned int frame,
+ uint64_t usec)
+{
+ xorg_list_del(&e->list);
+ if (e->handler) {
+ e->handler(e->crtc, frame, usec, e->data);
+ } else
+ e->abort(e->crtc, e->data);
+ free(e);
+}
+
/*
* Handle a DRM event
*/
@@ -66,19 +81,80 @@ amdgpu_drm_queue_handler(int fd, unsigned int frame, unsigned int sec,
xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue, list) {
if (e->seq == seq) {
- xorg_list_del(&e->list);
- if (e->handler)
- e->handler(e->crtc, frame,
- (uint64_t)sec * 1000000 + usec,
- e->data);
- else
- e->abort(e->crtc, e->data);
- free(e);
+ amdgpu_drm_queue_handle_one(e, frame, (uint64_t)sec *
+ 1000000 + usec);
break;
}
}
}
+/*
+ * Handle a DRM vblank event
+ */
+static void
+amdgpu_drm_queue_vblank_handler(int fd, unsigned int frame, unsigned int sec,
+ unsigned int usec, void *user_ptr)
+{
+ uintptr_t seq = (uintptr_t)user_ptr;
+ struct amdgpu_drm_queue_entry *e, *tmp;
+
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue, list) {
+ if (e->seq == seq) {
+ AMDGPUInfoPtr info = AMDGPUPTR(e->crtc->scrn);
+ drmmode_ptr drmmode = &info->drmmode;
+
+ e->usec = (uint64_t)sec * 1000000 + usec;
+
+ if (drmmode->event_context.vblank_handler ==
+ amdgpu_drm_queue_vblank_handler) {
+ amdgpu_drm_queue_handle_one(e, frame, e->usec);
+ } else {
+ xorg_list_del(&e->list);
+ e->frame = frame;
+ xorg_list_append(&e->list,
+ &amdgpu_drm_queue_deferred);
+ }
+
+ break;
+ }
+ }
+}
+
+/*
+ * Re-queue a DRM vblank event for deferred handling
+ */
+static void
+amdgpu_drm_queue_vblank_defer(int fd, unsigned int frame, unsigned int sec,
+ unsigned int usec, void *user_ptr)
+{
+ amdgpu_drm_queue_vblank_handler(fd, frame, sec, usec, user_ptr);
+}
+
+/*
+ * Handle deferred DRM vblank events
+ *
+ * This function must be called after amdgpu_drm_wait_pending_flip, once
+ * it's safe to attempt queueing a flip again
+ */
+void
+amdgpu_drm_queue_handle_deferred(xf86CrtcPtr crtc)
+{
+ drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
+ drmmode_ptr drmmode = drmmode_crtc->drmmode;
+ struct amdgpu_drm_queue_entry *e, *tmp;
+
+ if (drmmode_crtc->wait_flip_nesting_level == 0 ||
+ --drmmode_crtc->wait_flip_nesting_level > 0)
+ return;
+
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue_deferred, list) {
+ if (e->crtc == crtc)
+ amdgpu_drm_queue_handle_one(e, e->frame, e->usec);
+ }
+
+ drmmode->event_context.vblank_handler = amdgpu_drm_queue_vblank_handler;
+}
+
/*
* Enqueue a potential drm response; when the associated response
* appears, we've got data to pass to the handler from here
@@ -134,12 +210,17 @@ amdgpu_drm_abort_one(struct amdgpu_drm_queue_entry *e)
void
amdgpu_drm_abort_client(ClientPtr client)
{
- struct amdgpu_drm_queue_entry *e;
+ struct amdgpu_drm_queue_entry *e, *tmp;
xorg_list_for_each_entry(e, &amdgpu_drm_queue, list) {
if (e->client == client)
e->handler = NULL;
}
+
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue_deferred, list) {
+ if (e->client == client)
+ amdgpu_drm_abort_one(e);
+ }
}
/*
@@ -153,6 +234,13 @@ amdgpu_drm_abort_entry(uintptr_t seq)
if (seq == AMDGPU_DRM_QUEUE_ERROR)
return;
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue_deferred, list) {
+ if (e->seq == seq) {
+ amdgpu_drm_abort_one(e);
+ return;
+ }
+ }
+
xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue, list) {
if (e->seq == seq) {
amdgpu_drm_abort_one(e);
@@ -169,6 +257,13 @@ amdgpu_drm_abort_id(uint64_t id)
{
struct amdgpu_drm_queue_entry *e, *tmp;
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue_deferred, list) {
+ if (e->id == id) {
+ amdgpu_drm_abort_one(e);
+ break;
+ }
+ }
+
xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue, list) {
if (e->id == id) {
amdgpu_drm_abort_one(e);
@@ -186,6 +281,9 @@ void amdgpu_drm_wait_pending_flip(xf86CrtcPtr crtc)
AMDGPUEntPtr pAMDGPUEnt = AMDGPUEntPriv(crtc->scrn);
drmmode_ptr drmmode = drmmode_crtc->drmmode;
+ drmmode_crtc->wait_flip_nesting_level++;
+ drmmode->event_context.vblank_handler = amdgpu_drm_queue_vblank_defer;
+
while (drmmode_crtc->flip_pending &&
drmHandleEvent(pAMDGPUEnt->fd, &drmmode->event_context) > 0);
}
@@ -200,13 +298,14 @@ amdgpu_drm_queue_init(ScrnInfoPtr scrn)
drmmode_ptr drmmode = &info->drmmode;
drmmode->event_context.version = 2;
- drmmode->event_context.vblank_handler = amdgpu_drm_queue_handler;
+ drmmode->event_context.vblank_handler = amdgpu_drm_queue_vblank_handler;
drmmode->event_context.page_flip_handler = amdgpu_drm_queue_handler;
if (amdgpu_drm_queue_refcnt++)
return;
xorg_list_init(&amdgpu_drm_queue);
+ xorg_list_init(&amdgpu_drm_queue_deferred);
}
/*
@@ -222,5 +321,10 @@ amdgpu_drm_queue_close(ScrnInfoPtr scrn)
amdgpu_drm_abort_one(e);
}
+ xorg_list_for_each_entry_safe(e, tmp, &amdgpu_drm_queue_deferred, list) {
+ if (e->crtc->scrn == scrn)
+ amdgpu_drm_abort_one(e);
+ }
+
amdgpu_drm_queue_refcnt--;
}
diff --git a/src/amdgpu_drm_queue.h b/src/amdgpu_drm_queue.h
index cb6d5ff59..75609e39b 100644
--- a/src/amdgpu_drm_queue.h
+++ b/src/amdgpu_drm_queue.h
@@ -42,6 +42,7 @@ typedef void (*amdgpu_drm_handler_proc)(xf86CrtcPtr crtc, uint32_t seq,
uint64_t usec, void *data);
typedef void (*amdgpu_drm_abort_proc)(xf86CrtcPtr crtc, void *data);
+void amdgpu_drm_queue_handle_deferred(xf86CrtcPtr crtc);
uintptr_t amdgpu_drm_queue_alloc(xf86CrtcPtr crtc, ClientPtr client,
uint64_t id, void *data,
amdgpu_drm_handler_proc handler,
diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 615d3be8f..3b2de6839 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -305,6 +305,9 @@ drmmode_do_crtc_dpms(xf86CrtcPtr crtc, int mode)
nominal_frame_rate /= pix_in_frame;
drmmode_crtc->dpms_last_fps = nominal_frame_rate;
}
+
+ drmmode_crtc->dpms_mode = mode;
+ amdgpu_drm_queue_handle_deferred(crtc);
} else if (drmmode_crtc->dpms_mode != DPMSModeOn && mode == DPMSModeOn) {
/*
* Off->On transition: calculate and accumulate the
@@ -322,8 +325,9 @@ drmmode_do_crtc_dpms(xf86CrtcPtr crtc, int mode)
drmmode_crtc->interpolated_vblanks += delta_seq;
}
+
+ drmmode_crtc->dpms_mode = DPMSModeOn;
}
- drmmode_crtc->dpms_mode = mode;
}
static void
@@ -1415,6 +1419,7 @@ done:
}
}
+ amdgpu_drm_queue_handle_deferred(crtc);
return ret;
}
@@ -2320,11 +2325,6 @@ drmmode_output_set_tear_free(AMDGPUEntPtr pAMDGPUEnt,
drmmode_output->tear_free = tear_free;
if (crtc) {
- /* Wait for pending flips before drmmode_set_mode_major calls
- * drmmode_crtc_update_tear_free, to prevent a nested
- * drmHandleEvent call, which would hang
- */
- amdgpu_drm_wait_pending_flip(crtc);
drmmode_set_mode_major(crtc, &crtc->mode, crtc->rotation,
crtc->x, crtc->y);
}
@@ -3861,6 +3861,7 @@ Bool amdgpu_do_pageflip(ScrnInfoPtr scrn, ClientPtr client,
int i;
uint32_t flip_flags = flip_sync == FLIP_ASYNC ? DRM_MODE_PAGE_FLIP_ASYNC : 0;
drmmode_flipdata_ptr flipdata;
+ Bool handle_deferred = FALSE;
uintptr_t drm_queue_seq = 0;
flipdata = calloc(1, sizeof(drmmode_flipdata_rec));
@@ -3942,6 +3943,7 @@ Bool amdgpu_do_pageflip(ScrnInfoPtr scrn, ClientPtr client,
if (drmmode_crtc->scanout_update_pending) {
amdgpu_drm_wait_pending_flip(crtc);
+ handle_deferred = TRUE;
amdgpu_drm_abort_entry(drmmode_crtc->scanout_update_pending);
drmmode_crtc->scanout_update_pending = 0;
}
@@ -3975,6 +3977,8 @@ Bool amdgpu_do_pageflip(ScrnInfoPtr scrn, ClientPtr client,
drm_queue_seq = 0;
}
+ if (handle_deferred)
+ amdgpu_drm_queue_handle_deferred(ref_crtc);
if (flipdata->flip_count > 0)
return TRUE;
@@ -3995,5 +3999,7 @@ error:
xf86DrvMsg(scrn->scrnIndex, X_WARNING, "Page flip failed: %s\n",
strerror(errno));
+ if (handle_deferred)
+ amdgpu_drm_queue_handle_deferred(ref_crtc);
return FALSE;
}
diff --git a/src/drmmode_display.h b/src/drmmode_display.h
index 8b949f79d..28d15e282 100644
--- a/src/drmmode_display.h
+++ b/src/drmmode_display.h
@@ -119,6 +119,10 @@ typedef struct {
/* Modeset needed for DPMS on */
Bool need_modeset;
+ /* For keeping track of nested calls to drm_wait_pending_flip /
+ * drm_queue_handle_deferred
+ */
+ int wait_flip_nesting_level;
/* A flip to this FB is pending for this CRTC */
struct drmmode_fb *flip_pending;
/* The FB currently being scanned out by this CRTC, if any */
--
2.18.0
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