Messages in this thread |  | | Subject | Re: [PATCH 1/3] drm: Widen vblank count to 64 bits. Change vblank time precision to ns | From | Michel Dänzer <> | Date | Thu, 6 Jul 2017 16:45:10 +0900 |
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On 06/07/17 07:10 AM, Keith Packard wrote: > This modifies the datatypes used by the vblank code to provide both 64 > bits of vblank count and to increase the resolution of the vblank > timestamp from microseconds to nanoseconds. > > The driver interfaces have also been changed to return 64-bits of > vblank count; fortunately all of the code necessary to widen that value > was already included to handle devices returning fewer than 32-bits. > > This will provide the necessary datatypes for the Vulkan API. > > Signed-off-by: Keith Packard <keithp@keithp.com>
[...]
> @@ -1492,9 +1515,11 @@ int drm_wait_vblank(struct drm_device *dev, void *data, > > switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) { > case _DRM_VBLANK_RELATIVE: > - vblwait->request.sequence += seq; > + req_seq = seq + vblwait->request.sequence; > vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
Subtle breakage here: vblwait->request.sequence must still get updated for _DRM_VBLANK_RELATIVE, in case we're interrupted by a signal.
> @@ -317,6 +317,9 @@ int via_driver_irq_postinstall(struct drm_device *dev) > if (!dev_priv) > return -EINVAL; > > + if (dev->driver->get_vblank_counter) > + dev->max_vblank_count = 0xffffffff;
What's the purpose of this? All drivers providing get_vblank_counter should already initialize max_vblank_count correctly.
-- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer
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