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Farhan Ali authored
[ Upstream commit d1ffa760 ] The quiesce function calls cio_cancel_halt_clear() and if we get an -EBUSY we go into a loop where we: - wait for any interrupts - flush all I/O in the workqueue - retry cio_cancel_halt_clear During the period where we are waiting for interrupts or flushing all I/O, the channel subsystem could have completed a halt/clear action and turned off the corresponding activity control bits in the subchannel status word. This means the next time we call cio_cancel_halt_clear(), we will again start by calling cancel subchannel and so we can be stuck between calling cancel and halt forever. Rather than calling cio_cancel_halt_clear() immediately after waiting, let's try to disable the subchannel. If we succeed in disabling the subchannel then we know nothing else can happen with the device. Suggested-by:
Eric Farman <farman@linux.ibm.com> Signed-off-by:
Farhan Ali <alifm@linux.ibm.com> Message-Id: <4d5a4b98ab1b41ac6131b5c36de18b76c5d66898.1555449329.git.alifm@linux.ibm.com> Reviewed-by:
Eric Farman <farman@linux.ibm.com> Acked-by:
Halil Pasic <pasic@linux.ibm.com> Signed-off-by:
Cornelia Huck <cohuck@redhat.com> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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