From b55bf248581dc66321b24b29f199f6dc8d02db1b Mon Sep 17 00:00:00 2001 From: Christopher James Halse Rogers Date: Mon, 6 Dec 2010 11:24:00 +1100 Subject: Xext: Fix edge case with {Positive, Negative}Transition triggers. The {Positive,Negative}Transition triggers only fire when the counter goes from strictly {below,above} the threshold. If SyncComputeBracketValues gets called exactly at this threshold we may update the bracket values so that the counter is not updated past the threshold. Signed-off-by: Christopher James Halse Rogers Reviewed-by: Adam Jackson Signed-off-by: Keith Packard --- Xext/sync.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'Xext') diff --git a/Xext/sync.c b/Xext/sync.c index ab8f20d5c..7ea8a44fa 100644 --- a/Xext/sync.c +++ b/Xext/sync.c @@ -1059,6 +1059,17 @@ SyncComputeBracketValues(SyncCounter *pCounter) { psci->bracket_less = pTrigger->test_value; pnewltval = &psci->bracket_less; + } else if (XSyncValueEqual(pCounter->value, pTrigger->test_value) && + XSyncValueLessThan(pTrigger->test_value, + psci->bracket_greater)) + { + /* + * The value is exactly equal to our threshold. We want one + * more event in the positive direction to ensure we pick up + * when the value *exceeds* this threshold. + */ + psci->bracket_greater = pTrigger->test_value; + pnewgtval = &psci->bracket_greater; } } else if (pTrigger->test_type == XSyncPositiveTransition && @@ -1069,6 +1080,17 @@ SyncComputeBracketValues(SyncCounter *pCounter) { psci->bracket_greater = pTrigger->test_value; pnewgtval = &psci->bracket_greater; + } else if (XSyncValueEqual(pCounter->value, pTrigger->test_value) && + XSyncValueGreaterThan(pTrigger->test_value, + psci->bracket_less)) + { + /* + * The value is exactly equal to our threshold. We want one + * more event in the negative direction to ensure we pick up + * when the value is less than this threshold. + */ + psci->bracket_less = pTrigger->test_value; + pnewltval = &psci->bracket_less; } } } /* end for each trigger */ -- cgit v1.2.3