[Skiboot] [PATCH] PHB3: Fix unexpected ER (all) on errinjct by PCI config

[Gavin Shan]

This issue was found on SRIOV VFs initially and then I checked
with Chad Larson who put much efforts to sort it out. As more
experiments I did, the issue isn't limited to SRIOV VFs. That
means the isue can be seen on non-SRIOV adapter as well: Firstly,
I ensure that outbound request discard interrupt (bit#12) is
enabled in PCI Express Port Interrupt Enable Register (offset:
0x558). Then injecting error to root complex by PAPR Error
Injection Registers with PCI config read. Eventually, all (256)
PEs are frozen. After clearing the bit, the target PE#0 is frozen
as expected. As Chad pointed, the interrupt ("outbound request
discard") is always raised during the error injection, which is
translated to UTL's primary interrupt to freeze all (256) PEs.

This drops bit#12 of PCI Express Port Interrupt Enable Register
to avoid the UTL's primary interrupt caused by outbound request
discard, in order to avoid freezing all (256) PEs during error
injection via PCI config read.

Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 hw/phb3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/phb3.c b/hw/phb3.c
index 71c64be..d57cbd9 100644
--- a/hw/phb3.c
+++ b/hw/phb3.c
@@ -2031,7 +2031,7 @@ static void phb3_setup_for_link_up(struct phb3 *p)
 
 	/* Clear spurrious errors and enable PCIE port interrupts */
 	out_be64(p->regs + UTL_PCIE_PORT_STATUS, 0xffdfffffffffffff);
-	out_be64(p->regs + UTL_PCIE_PORT_IRQ_EN, 0xad5a800000000000);
+	out_be64(p->regs + UTL_PCIE_PORT_IRQ_EN, 0xad52800000000000);
 
 	/* Mark link up */
 	p->has_link = true;
@@ -3834,7 +3834,7 @@ static void phb3_init_utl(struct phb3 *p)
 	out_be64(p->regs + UTL_PCIE_PORT_ERROR_SEV,        0x5039000000000000);
 
 	if (p->has_link)
-		out_be64(p->regs + UTL_PCIE_PORT_IRQ_EN,   0xad5a800000000000);
+		out_be64(p->regs + UTL_PCIE_PORT_IRQ_EN,   0xad52800000000000);
 	else
 		out_be64(p->regs + UTL_PCIE_PORT_IRQ_EN,   0xad42800000000000);
 
-- 
2.1.0