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authorJiri Kosina <jkosina@suse.cz>2010-12-22 12:57:02 -0500
committerJiri Kosina <jkosina@suse.cz>2010-12-22 12:57:02 -0500
commit4b7bd364700d9ac8372eff48832062b936d0793b (patch)
tree0dbf78c95456a0b02d07fcd473281f04a87e266d /arch/x86/kernel/hpet.c
parentc0d8768af260e2cbb4bf659ae6094a262c86b085 (diff)
parent90a8a73c06cc32b609a880d48449d7083327e11a (diff)
Merge branch 'master' into for-next
Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
Diffstat (limited to 'arch/x86/kernel/hpet.c')
-rw-r--r--arch/x86/kernel/hpet.c26
1 files changed, 16 insertions, 10 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index ae03cab4352e..4ff5968f12d2 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -27,6 +27,9 @@
27#define HPET_DEV_FSB_CAP 0x1000 27#define HPET_DEV_FSB_CAP 0x1000
28#define HPET_DEV_PERI_CAP 0x2000 28#define HPET_DEV_PERI_CAP 0x2000
29 29
30#define HPET_MIN_CYCLES 128
31#define HPET_MIN_PROG_DELTA (HPET_MIN_CYCLES + (HPET_MIN_CYCLES >> 1))
32
30#define EVT_TO_HPET_DEV(evt) container_of(evt, struct hpet_dev, evt) 33#define EVT_TO_HPET_DEV(evt) container_of(evt, struct hpet_dev, evt)
31 34
32/* 35/*
@@ -299,8 +302,9 @@ static void hpet_legacy_clockevent_register(void)
299 /* Calculate the min / max delta */ 302 /* Calculate the min / max delta */
300 hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, 303 hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
301 &hpet_clockevent); 304 &hpet_clockevent);
302 /* 5 usec minimum reprogramming delta. */ 305 /* Setup minimum reprogramming delta. */
303 hpet_clockevent.min_delta_ns = 5000; 306 hpet_clockevent.min_delta_ns = clockevent_delta2ns(HPET_MIN_PROG_DELTA,
307 &hpet_clockevent);
304 308
305 /* 309 /*
306 * Start hpet with the boot cpu mask and make it 310 * Start hpet with the boot cpu mask and make it
@@ -393,22 +397,24 @@ static int hpet_next_event(unsigned long delta,
393 * the wraparound into account) nor a simple count down event 397 * the wraparound into account) nor a simple count down event
394 * mode. Further the write to the comparator register is 398 * mode. Further the write to the comparator register is
395 * delayed internally up to two HPET clock cycles in certain 399 * delayed internally up to two HPET clock cycles in certain
396 * chipsets (ATI, ICH9,10). We worked around that by reading 400 * chipsets (ATI, ICH9,10). Some newer AMD chipsets have even
397 * back the compare register, but that required another 401 * longer delays. We worked around that by reading back the
398 * workaround for ICH9,10 chips where the first readout after 402 * compare register, but that required another workaround for
399 * write can return the old stale value. We already have a 403 * ICH9,10 chips where the first readout after write can
400 * minimum delta of 5us enforced, but a NMI or SMI hitting 404 * return the old stale value. We already had a minimum
405 * programming delta of 5us enforced, but a NMI or SMI hitting
401 * between the counter readout and the comparator write can 406 * between the counter readout and the comparator write can
402 * move us behind that point easily. Now instead of reading 407 * move us behind that point easily. Now instead of reading
403 * the compare register back several times, we make the ETIME 408 * the compare register back several times, we make the ETIME
404 * decision based on the following: Return ETIME if the 409 * decision based on the following: Return ETIME if the
405 * counter value after the write is less than 8 HPET cycles 410 * counter value after the write is less than HPET_MIN_CYCLES
406 * away from the event or if the counter is already ahead of 411 * away from the event or if the counter is already ahead of
407 * the event. 412 * the event. The minimum programming delta for the generic
413 * clockevents code is set to 1.5 * HPET_MIN_CYCLES.
408 */ 414 */
409 res = (s32)(cnt - hpet_readl(HPET_COUNTER)); 415 res = (s32)(cnt - hpet_readl(HPET_COUNTER));
410 416
411 return res < 8 ? -ETIME : 0; 417 return res < HPET_MIN_CYCLES ? -ETIME : 0;
412} 418}
413 419
414static void hpet_legacy_set_mode(enum clock_event_mode mode, 420static void hpet_legacy_set_mode(enum clock_event_mode mode,