[Skiboot] [PATCH] Added a 5ms wait after a msi-irq is masked

Philippe Bergheaud felix at linux.vnet.ibm.com
Tue Mar 22 21:46:53 AEDT 2016

From: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>

Adds a 5ms wait to phb3_msi_set_xive after the interrupt is masked so
that the kernel delays cleanup until an irq if its in-flight is
handled. The value 5ms is the worst case time needed by an irq to be
presented to the host after its generated.

Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>
This patch requires the following patches:

 hw/phb3.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/phb3.c b/hw/phb3.c
index fbdcb9e..e5d49b2 100644
--- a/hw/phb3.c
+++ b/hw/phb3.c
@@ -1751,6 +1751,8 @@ static int64_t phb3_msi_set_xive(void *data,
 		out_be64(p->regs + PHB_IVC_UPDATE, ivc);
+		/* wait for 5ms before signalling the interrupt is masked */
+		time_wait_ms(5);
 	return OPAL_SUCCESS;

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