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authorJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2021-01-15 08:49:57 +0200
committerJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2021-01-15 08:49:57 +0200
commitd263dfa7d2697a43f3299b9731cd568ee49cdd2c (patch)
treef5d993c7000ac41ee926acf0b357ec572ef7908f /drivers/clocksource/arm_arch_timer.c
parentdrm/i915/gt: Prune inlines (diff)
parentMerge tag 'drm-intel-gt-next-2021-01-14' of git://anongit.freedesktop.org/drm/drm-intel into drm-next (diff)
downloadwireguard-linux-d263dfa7d2697a43f3299b9731cd568ee49cdd2c.tar.xz
wireguard-linux-d263dfa7d2697a43f3299b9731cd568ee49cdd2c.zip
Merge drm/drm-next into drm-intel-gt-next
Backmerging to get a common base for merging topic branches between drm-intel-next and drm-intel-gt-next. Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
-rw-r--r--drivers/clocksource/arm_arch_timer.c27
1 files changed, 18 insertions, 9 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 6c3e84180146..d0177824c518 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -396,10 +396,10 @@ static void erratum_set_next_event_tval_generic(const int access, unsigned long
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
if (access == ARCH_TIMER_PHYS_ACCESS) {
- cval = evt + arch_counter_get_cntpct();
+ cval = evt + arch_counter_get_cntpct_stable();
write_sysreg(cval, cntp_cval_el0);
} else {
- cval = evt + arch_counter_get_cntvct();
+ cval = evt + arch_counter_get_cntvct_stable();
write_sysreg(cval, cntv_cval_el0);
}
@@ -822,15 +822,24 @@ static void arch_timer_evtstrm_enable(int divider)
static void arch_timer_configure_evtstream(void)
{
- int evt_stream_div, pos;
+ int evt_stream_div, lsb;
+
+ /*
+ * As the event stream can at most be generated at half the frequency
+ * of the counter, use half the frequency when computing the divider.
+ */
+ evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ / 2;
+
+ /*
+ * Find the closest power of two to the divisor. If the adjacent bit
+ * of lsb (last set bit, starts from 0) is set, then we use (lsb + 1).
+ */
+ lsb = fls(evt_stream_div) - 1;
+ if (lsb > 0 && (evt_stream_div & BIT(lsb - 1)))
+ lsb++;
- /* Find the closest power of two to the divisor */
- evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
- pos = fls(evt_stream_div);
- if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
- pos--;
/* enable event stream */
- arch_timer_evtstrm_enable(min(pos, 15));
+ arch_timer_evtstrm_enable(max(0, min(lsb, 15)));
}
static void arch_counter_set_user_access(void)