Re: [PATCH 1/2 V2] iommu/amd: Add workaround for ERBT1312

[Suravee Suthikulpanit]

On 4/18/2013 1:35 PM, Joerg Roedel wrote:
> On Thu, Apr 18, 2013 at 11:59:58AM -0500, Suthikulpanit, Suravee wrote:
> > One last concern I have for this patch is the case when we re-enable
> > the interrupt, then another interrupt happens while we processing
> > the log and set the bit.  If the interrupt thread doesn't check this
> > right before the thread exits the handler.  We could still end up
> > leaving the interrupt disabled.
> That can't happen, the patch checks whether the bit is really 0 and then
> it processes the event/ppr-log entries. If any new entry is queued while
> we process the logs another interrupt will be fired and the irq-thread
> will run again. So we will not miss any log entry.
According to the "kernel/irq/handle.c:irq_wake_thread()", I thought that 
for the threaded IRQ, if the system getting a new interrupt from the 
device while the thread is running, it will just return and do nothing.

Suravee

> 	Joerg


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