[Skiboot] [PATCH v2 5/7] npu2-opencapi: ODL should be in reset when enabled

Frederic Barrat fbarrat at linux.ibm.com
Wed Mar 13 07:35:13 AEDT 2019

We haven't hit any problem so far, but from the ODL designer, the ODL
should be in reset when it is enabled.

The ODL remains in reset until we start a fundamental reset to
initiate link training. We still assert and deassert the ODL reset
signal as part of the normal procedure just before training the
link. Asserting is therefore useless at boot, since the ODL is already
in reset, but we keep it as it's only a scom write and it's needed
when we reset/retrain from the OS.

Signed-off-by: Frederic Barrat <fbarrat at linux.ibm.com>

v2: update commit message

 hw/npu2-opencapi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/npu2-opencapi.c b/hw/npu2-opencapi.c
index 87e64492..223888e6 100644
--- a/hw/npu2-opencapi.c
+++ b/hw/npu2-opencapi.c
@@ -308,6 +308,12 @@ static void enable_odl_phy_mux(uint32_t gcid, int index)
+	/*
+	 * ODL must be in reset when enabling.
+	 * It stays in reset until the link is trained
+	 */
+	assert_odl_reset(gcid, index);
 	/* PowerBus OLL PHY Training Config Register */
 	xscom_read(gcid, phy_config_scom, &reg);

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