[PATCH 4.18 174/235] liquidio: fix hang when re-binding VF host drv after running DPDK VF driver

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rick Farrington <ricardo.farrington@xxxxxxxxxx>

[ Upstream commit ac13d6d8eaded15c67265eafc32f439ea3a0ac4a ]

When configuring SLI_PKTn_OUTPUT_CONTROL, VF driver was assuming that IPTR
mode was disabled by reset, which was not true.  Since DPDK driver had
set IPTR mode previously, the VF driver (which uses buf-ptr-only mode) was
not properly handling DROQ packets (i.e. it saw zero-length packets).

This represented an invalid hardware configuration which the driver could
not handle.

Signed-off-by: Rick Farrington <ricardo.farrington@xxxxxxxxxx>
Signed-off-by: Felix Manlunas <felix.manlunas@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c |    3 +++
 drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c |    3 +++
 2 files changed, 6 insertions(+)

--- a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
+++ b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
@@ -493,6 +493,9 @@ static void cn23xx_pf_setup_global_outpu
 	for (q_no = srn; q_no < ern; q_no++) {
 		reg_val = octeon_read_csr(oct, CN23XX_SLI_OQ_PKT_CONTROL(q_no));
 
+		/* clear IPTR */
+		reg_val &= ~CN23XX_PKT_OUTPUT_CTL_IPTR;
+
 		/* set DPTR */
 		reg_val |= CN23XX_PKT_OUTPUT_CTL_DPTR;
 
--- a/drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c
+++ b/drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c
@@ -165,6 +165,9 @@ static void cn23xx_vf_setup_global_outpu
 		reg_val =
 		    octeon_read_csr(oct, CN23XX_VF_SLI_OQ_PKT_CONTROL(q_no));
 
+		/* clear IPTR */
+		reg_val &= ~CN23XX_PKT_OUTPUT_CTL_IPTR;
+
 		/* set DPTR */
 		reg_val |= CN23XX_PKT_OUTPUT_CTL_DPTR;