diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-01 00:55:55 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-23 20:12:12 +1000 |
| commit | cfb5946b55f1dfd19e042feae1fbff6041e25a98 (patch) | |
| tree | d350deb9be88f842127116625c68ad0b5c093f04 /drivers/tty | |
| parent | ec97eaad1383ab2500fcf9a07ade6044fbcc67f5 (diff) | |
| download | lwn-cfb5946b55f1dfd19e042feae1fbff6041e25a98.tar.gz lwn-cfb5946b55f1dfd19e042feae1fbff6041e25a98.zip | |
tty: hvc: hvc_poll() may sleep
Introduce points where hvc_poll drops the lock, enables interrupts,
and reschedules.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 745ac220fce8..2abfc0b15fbb 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -589,7 +589,7 @@ static u32 timeout = MIN_TIMEOUT; #define HVC_POLL_READ 0x00000001 #define HVC_POLL_WRITE 0x00000002 -int hvc_poll(struct hvc_struct *hp) +static int __hvc_poll(struct hvc_struct *hp, bool may_sleep) { struct tty_struct *tty; int i, n, count, poll_mask = 0; @@ -611,6 +611,12 @@ int hvc_poll(struct hvc_struct *hp) timeout = (written_total) ? 0 : MIN_TIMEOUT; } + if (may_sleep) { + spin_unlock_irqrestore(&hp->lock, flags); + cond_resched(); + spin_lock_irqsave(&hp->lock, flags); + } + /* No tty attached, just skip */ tty = tty_port_tty_get(&hp->port); if (tty == NULL) @@ -698,6 +704,11 @@ int hvc_poll(struct hvc_struct *hp) return poll_mask; } + +int hvc_poll(struct hvc_struct *hp) +{ + return __hvc_poll(hp, false); +} EXPORT_SYMBOL_GPL(hvc_poll); /** @@ -736,7 +747,8 @@ static int khvcd(void *unused) if (!cpus_are_in_xmon()) { mutex_lock(&hvc_structs_mutex); list_for_each_entry(hp, &hvc_structs, next) { - poll_mask |= hvc_poll(hp); + poll_mask |= __hvc_poll(hp, true); + cond_resched(); } mutex_unlock(&hvc_structs_mutex); } else |