[Skiboot] [PATCH 1/5] phb4: Workaround PHB errata with CFG write UR/CA errors

[Benjamin Herrenschmidt]

If the PHB encounters a UR or CA status on a CFG write, it will
incorrectly freeze the wrong PE. Instead of using the PE# specified
in the CONFIG_ADDRESS register, it will use the PE# of whatever
MMIO occurred last.

Work around this disabling freeze on such errors

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
 hw/phb4.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/hw/phb4.c b/hw/phb4.c
index 5e07e2bc..c329e5a2 100644
--- a/hw/phb4.c
+++ b/hw/phb4.c
@@ -4686,7 +4686,11 @@ static void phb4_init_errors(struct phb4 *p)
 	out_be64(p->regs + 0x0d00,	0xffffffffffffffffull);
 	out_be64(p->regs + 0x0d08,	0x0000000000000000ull);
 	out_be64(p->regs + 0x0d18,	0xffffff0fffffffffull);
-	out_be64(p->regs + 0x0d28,	0x0000400a00000000ull);
+
+	/* Errata: Clear bit 17, otherwise a CFG write UR/CA will incorrectly
+	 * freeze a "random" PE (whatever last PE did an MMIO)
+	 */
+	out_be64(p->regs + 0x0d28,	0x0000000a00000000ull);
 	out_be64(p->regs + 0x0d30,	0xdff7bd05f7ddfff0ull); /* XXX CAPI has diff. value */
 	out_be64(p->regs + 0x0d40,	0x0000000000000000ull);
 	out_be64(p->regs + 0x0d48,	0x0000000000000000ull);
-- 
2.17.1