On Mon, 23 May 2011, Thomas Goetz wrote:
> I'm running with the attached workaround and I'm the PS/2 issue is gone.
>
> drivers/xen/events.c :: xen_map_pirq_gsi
>
> if ((strcmp(name, "ioapic-edge") != 0) && pirq_needs_eoi(irq)) {
> set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
> handle_fasteoi_irq, name);
> } else {
> set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
> handle_edge_irq, name);
> }
I had the same idea while reading your previous email.
I think the following patch is better than strcmp name:
---
Use the trigger info we already have to choose the irq handler
Do not use pirq_needs_eoi to decide which irq handler to use because Xen
always returns true if the guest does not support pirq_eoi_map.
Use the trigger information we already have from MP-tables and ACPI.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7f676f8..8418398 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -627,6 +627,9 @@ int xen_allocate_pirq_gsi(unsigned gsi)
*
* Note: We don't assign an event channel until the irq actually started
* up. Return an existing irq if we've already got one for the gsi.
+ *
+ * Shareable implies level triggered, not shareable implies edge
+ * triggered here.
*/
int xen_bind_pirq_gsi_to_irq(unsigned gsi,
unsigned pirq, int shareable, char *name)
@@ -665,16 +668,13 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
pirq_query_unmask(irq);
/* We try to use the handler with the appropriate semantic for the
- * type of interrupt: if the interrupt doesn't need an eoi
- * (pirq_needs_eoi returns false), we treat it like an edge
- * triggered interrupt so we use handle_edge_irq.
- * As a matter of fact this only happens when the corresponding
- * physical interrupt is edge triggered or an msi.
+ * type of interrupt: if the interrupt is an edge triggered
+ * interrupt we use handle_edge_irq.
*
- * On the other hand if the interrupt needs an eoi (pirq_needs_eoi
- * returns true) we treat it like a level triggered interrupt so we
- * use handle_fasteoi_irq like the native code does for this kind of
+ * On the other hand if the interrupt is level triggered we use
+ * handle_fasteoi_irq like the native code does for this kind of
* interrupts.
+ *
* Depending on the Xen version, pirq_needs_eoi might return true
* not only for level triggered interrupts but for edge triggered
* interrupts too. In any case Xen always honors the eoi mechanism,
@@ -682,7 +682,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
* hasn't received an eoi yet. Therefore using the fasteoi handler
* is the right choice either way.
*/
- if (pirq_needs_eoi(irq))
+ if (shareable)
irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
handle_fasteoi_irq, name);
else
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