Current pciehp implementation disables and re-enables hotplug interrupts
in its interrupt handler. This operation might be intend to guarantee
that interrupts for the events newly occured during previous events are
being handled will be successfully generated. But current implementaion
has the following prolems.
- Current interrupt service routin clears status changes without
waiting command completion. Because of this, events might not be
cleared properly.
- Current interrupt service routine clears status changes caused by
disabling or enabling hotplug interrupts itself. This will lose new
events that occurs during previous interrupts are being handled.
- Current implementation doesn't have any serialization mechanism
between the code to wait for command completion and the interrupt
handler that clears the command completion events caused by itself.
There is clearly race conditions between them, and it may cause
the problem that waiting for command completion doesn't work for
example.
To fix those problems, this patch stops disabling/re-enabling hotplug
interrupts in interrupt service routine. Instead of this, this patch
re-inspects Slot Status register after clearing what is presumed to
be the last bending interrupt in order to guarantee that all interrupt
events are serviced.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
c6b069e946