s390/qeth: wake up all waiters from qeth_irq()

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card->wait_q is shared by different users, for different wake-up
conditions. qeth_irq() can potentially trigger multiple of these
conditions:
1) A change to channel->irq_pending, which qeth_send_control_data() is
   waiting for.
2) A change to card->state, which qeth_clear_channel() and
   qeth_halt_channel() are waiting for.

As qeth_irq() does only a single wake_up(), we might miss to wake up
a second eligible waiter. Luckily all waiters are guarded with a
timeout, so this situation should recover on its own eventually.

To make things work robustly, add an additional wake_up() for changes
to channel->state. And extract a helper that updates
channel->irq_pending along with the needed wake_up().

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

This commit is contained in:

Julian Wiedmann 2019-12-18 17:34:43 +01:00 • committed by David S. Miller

parent 871602b107

commit 7359393f3c

2 changed files with 18 additions and 16 deletions

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7

drivers/s390/net/qeth_core.h

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27

drivers/s390/net/qeth_core_main.c

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