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| author | Joel Stanley <joel@jms.id.au> | 2018-11-27 08:23:56 +0300 |
|---|---|---|
| committer | Joel Stanley <joel@jms.id.au> | 2018-11-27 08:24:09 +0300 |
| commit | d608acfd4ac3fe17f3081bee8fcd4dcd896c2ffa (patch) | |
| tree | ade4450a72a2e358a1d2e5cde321de0097fb291c /drivers/clocksource/i8253.c | |
| parent | 62ccc3924eff37012bd0c227d8b7dc71188fc358 (diff) | |
| parent | a9da8725b7a744be3ff0ff44cab2547e4d1e6675 (diff) | |
| download | linux-dev-4.18.tar.xz | |
Merge tag 'v4.18.20' into dev-4.18dev-4.18
This is the 4.18.20 stable release
Signed-off-by: Joel Stanley <joel@jms.id.au>
Diffstat (limited to 'drivers/clocksource/i8253.c')
| -rw-r--r-- | drivers/clocksource/i8253.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c index 9c38895542f4..d4350bb10b83 100644 --- a/drivers/clocksource/i8253.c +++ b/drivers/clocksource/i8253.c @@ -20,6 +20,13 @@ DEFINE_RAW_SPINLOCK(i8253_lock); EXPORT_SYMBOL(i8253_lock); +/* + * Handle PIT quirk in pit_shutdown() where zeroing the counter register + * restarts the PIT, negating the shutdown. On platforms with the quirk, + * platform specific code can set this to false. + */ +bool i8253_clear_counter_on_shutdown __ro_after_init = true; + #ifdef CONFIG_CLKSRC_I8253 /* * Since the PIT overflows every tick, its not very useful @@ -109,8 +116,11 @@ static int pit_shutdown(struct clock_event_device *evt) raw_spin_lock(&i8253_lock); outb_p(0x30, PIT_MODE); - outb_p(0, PIT_CH0); - outb_p(0, PIT_CH0); + + if (i8253_clear_counter_on_shutdown) { + outb_p(0, PIT_CH0); + outb_p(0, PIT_CH0); + } raw_spin_unlock(&i8253_lock); return 0; |