xen/events: Fix interrupt lost during irq_disable and irq_enable
authorLiu Shuo <shuo.a.liu@intel.com>
Sat, 29 Jul 2017 16:59:57 +0000 (00:59 +0800)
committerJuergen Gross <jgross@suse.com>
Fri, 11 Aug 2017 14:46:01 +0000 (16:46 +0200)
commit020db9d3c1dc0aab9ab1252f4a36b6d8456b8794
tree65e78315c54d92e53bf27dc55a273ff17fd2b21e
parent529871bb3c0675d0b425e2070d5a739db097be98
xen/events: Fix interrupt lost during irq_disable and irq_enable

Here is a device has xen-pirq-MSI interrupt. Dom0 might lost interrupt
during driver irq_disable/irq_enable. Here is the scenario,
 1. irq_disable -> disable_dynirq -> mask_evtchn(irq channel)
 2. dev interrupt raised by HW and Xen mark its evtchn as pending
 3. irq_enable -> startup_pirq -> eoi_pirq ->
    clear_evtchn(channel of irq) -> clear pending status
 4. consume_one_event process the irq event without pending bit assert
    which result in interrupt lost once
 5. No HW interrupt raising anymore.

Now use enable_dynirq for enable_pirq of xen_pirq_chip to remove
eoi_pirq when irq_enable.

Signed-off-by: Liu Shuo <shuo.a.liu@intel.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
drivers/xen/events/events_base.c