3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
commit 26d766c60f4ea08cd14f0f3435a6db3d6cc2ae96 upstream.
The ccw_device_start in raw3215_start_io can fail. raw3215_try_io
does not check if the request could be started and removes any
pending timer. This can leave the system in a hanging state.
Check for pending request after raw3215_start_io and start a
timer if necessary.
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/s390/char/con3215.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -288,12 +288,16 @@ static void raw3215_timeout(unsigned lon
unsigned long flags;
spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
- if (raw->flags & RAW3215_TIMER_RUNS) {
- del_timer(&raw->timer);
- raw->flags &= ~RAW3215_TIMER_RUNS;
- if (!(raw->port.flags & ASYNC_SUSPENDED)) {
- raw3215_mk_write_req(raw);
- raw3215_start_io(raw);
+ raw->flags &= ~RAW3215_TIMER_RUNS;
+ if (!(raw->port.flags & ASYNC_SUSPENDED)) {
+ raw3215_mk_write_req(raw);
+ raw3215_start_io(raw);
+ if ((raw->queued_read || raw->queued_write) &&
+ !(raw->flags & RAW3215_WORKING) &&
+ !(raw->flags & RAW3215_TIMER_RUNS)) {
+ raw->timer.expires = RAW3215_TIMEOUT + jiffies;
+ add_timer(&raw->timer);
+ raw->flags |= RAW3215_TIMER_RUNS;
}
}
spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
@@ -317,17 +321,15 @@ static inline void raw3215_try_io(struct
(raw->flags & RAW3215_FLUSHING)) {
/* execute write requests bigger than minimum size */
raw3215_start_io(raw);
- if (raw->flags & RAW3215_TIMER_RUNS) {
- del_timer(&raw->timer);
- raw->flags &= ~RAW3215_TIMER_RUNS;
- }
- } else if (!(raw->flags & RAW3215_TIMER_RUNS)) {
- /* delay small writes */
- raw->timer.expires = RAW3215_TIMEOUT + jiffies;
- add_timer(&raw->timer);
- raw->flags |= RAW3215_TIMER_RUNS;
}
}
+ if ((raw->queued_read || raw->queued_write) &&
+ !(raw->flags & RAW3215_WORKING) &&
+ !(raw->flags & RAW3215_TIMER_RUNS)) {
+ raw->timer.expires = RAW3215_TIMEOUT + jiffies;
+ add_timer(&raw->timer);
+ raw->flags |= RAW3215_TIMER_RUNS;
+ }
}
/*
--
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