Commit 209e4dbc authored by Daniel Vetter's avatar Daniel Vetter

drm/vblank: Use u32 consistently for vblank counters

In

commit 99264a61
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Apr 15 19:34:43 2015 +0200

    drm/vblank: Fixup and document timestamp update/read barriers

I've switched vblank->count from atomic_t to unsigned long and
accidentally created an integer comparison bug in
drm_vblank_count_and_time since vblanke->count might overflow the u32
local copy and hence the retry loop never succeed.

Fix this by consistently using u32.

Cc: Michel Dänzer <michel@daenzer.net>
Reported-by: default avatarMichel Dänzer <michel@daenzer.net>
Reviewed-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
parent 047fe6e6
...@@ -75,7 +75,7 @@ module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600) ...@@ -75,7 +75,7 @@ module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600)
module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600); module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
static void store_vblank(struct drm_device *dev, int crtc, static void store_vblank(struct drm_device *dev, int crtc,
unsigned vblank_count_inc, u32 vblank_count_inc,
struct timeval *t_vblank) struct timeval *t_vblank)
{ {
struct drm_vblank_crtc *vblank = &dev->vblank[crtc]; struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
......
...@@ -691,7 +691,7 @@ struct drm_vblank_crtc { ...@@ -691,7 +691,7 @@ struct drm_vblank_crtc {
struct timer_list disable_timer; /* delayed disable timer */ struct timer_list disable_timer; /* delayed disable timer */
/* vblank counter, protected by dev->vblank_time_lock for writes */ /* vblank counter, protected by dev->vblank_time_lock for writes */
unsigned long count; u32 count;
/* vblank timestamps, protected by dev->vblank_time_lock for writes */ /* vblank timestamps, protected by dev->vblank_time_lock for writes */
struct timeval time[DRM_VBLANKTIME_RBSIZE]; struct timeval time[DRM_VBLANKTIME_RBSIZE];
......
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