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uxa: Remove the filtering of bogus Present MSC values 

If the intention was to filter the return values from the kernel, the
filtering would have been applied to the kernel values and not to the
incoming values from Present. This filtering introduces crazy integer
promotion and truncation bugs all because Present feeds garbage into its
vblank requests.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Chris Wilson 2015-02-13 08:06:43 +00:00
parent 35ab0afd04
commit 42ebe2ef96
1 changed files with 1 additions and 30 deletions
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31
src/uxa/intel_display.c
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@ -116,7 +116,6 @@ struct intel_crtc {
struct list link;
PixmapPtr scanout_pixmap;
uint32_t scanout_fb_id;
int32_t vblank_offset;
uint32_t msc_prev;
uint64_t msc_high;
};
@ -1914,7 +1913,6 @@ intel_sequence_to_crtc_msc(xf86CrtcPtr crtc, uint32_t sequence)
{
struct intel_crtc *intel_crtc = crtc->driver_private;
sequence += intel_crtc->vblank_offset;
if ((int32_t) (sequence - intel_crtc->msc_prev) < -0x40000000)
intel_crtc->msc_high += 0x100000000L;
intel_crtc->msc_prev = sequence;
@ -1938,37 +1936,10 @@ intel_get_crtc_msc_ust(ScrnInfoPtr scrn, xf86CrtcPtr crtc, uint64_t *msc, uint64
return 0;
}
/*
* Convert a 64-bit adjusted MSC value into a 32-bit kernel sequence number,
* removing the high 32 bits and subtracting out the vblank_offset term.
*
* This also updates the vblank_offset when it notices that the value should
* change.
*/
#define MAX_VBLANK_OFFSET 1000
uint32_t
intel_crtc_msc_to_sequence(ScrnInfoPtr scrn, xf86CrtcPtr crtc, uint64_t expect)
{
struct intel_crtc *intel_crtc = crtc->driver_private;
uint64_t msc, ust;
if (intel_get_crtc_msc_ust(scrn, crtc, &msc, &ust) == 0) {
int64_t diff = expect - msc;
/* We're way off here, assume that the kernel has lost its mind
* and smack the vblank back to something sensible
*/
if (diff < -MAX_VBLANK_OFFSET || diff > MAX_VBLANK_OFFSET) {
intel_crtc->vblank_offset += (int32_t) diff;
if (intel_crtc->vblank_offset > -MAX_VBLANK_OFFSET &&
intel_crtc->vblank_offset < MAX_VBLANK_OFFSET)
intel_crtc->vblank_offset = 0;
}
}
return (uint32_t) (expect - intel_crtc->vblank_offset);
return (uint32_t)expect;
}
/*