[PATCH net-next] liquidio: fix hang when re-binding VF host drv after running DPDK VF driver

[Felix Manlunas <felix.manlunas@cavium.com>]

From: Rick Farrington <ricardo.farrington@cavium.com>

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@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
---
 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(+)

diff --git a/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c b/drivers/net/ethernet/cavium/liquidio/cn23xx_pf_device.c
index 929d485..e088ded 100644
--- 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_output_regs(struct octeon_device *oct)
 	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;
 
diff --git a/drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c b/drivers/net/ethernet/cavium/liquidio/cn23xx_vf_device.c
index 9338a00..1f8b7f6 100644
--- 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_output_regs(struct octeon_device *oct)
 		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;
 
-- 
1.8.3.1