[dpdk-dev] [PATCH v3 29/69] net/ice/base: always set prefena when configuring a Rx queue

[Leyi Rong]

Currently we are always setting prefena to 0. This is causing the
hardware to only fetch descriptors when there are none free in the cache
for a received packet instead of prefetching when it has used the last
descriptor regardless of incoming packets. Fix this by allowing the
hardware to prefetch Rx descriptors.

Signed-off-by: Brett Creeley <brett.cree...@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell...@intel.com>
Signed-off-by: Leyi Rong <leyi.r...@intel.com>
---
 drivers/net/ice/base/ice_common.c    | 9 ++++++++-
 drivers/net/ice/base/ice_lan_tx_rx.h | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ice/base/ice_common.c 
b/drivers/net/ice/base/ice_common.c
index 7cd0832bc..5490c1dfd 100644
--- a/drivers/net/ice/base/ice_common.c
+++ b/drivers/net/ice/base/ice_common.c
@@ -1213,6 +1213,7 @@ static const struct ice_ctx_ele ice_rlan_ctx_info[] = {
        ICE_CTX_STORE(ice_rlan_ctx, tphdata_ena,        1,      195),
        ICE_CTX_STORE(ice_rlan_ctx, tphhead_ena,        1,      196),
        ICE_CTX_STORE(ice_rlan_ctx, lrxqthresh,         3,      198),
+       ICE_CTX_STORE(ice_rlan_ctx, prefena,            1,      201),
        { 0 }
 };
 
@@ -1223,7 +1224,8 @@ static const struct ice_ctx_ele ice_rlan_ctx_info[] = {
  * @rxq_index: the index of the Rx queue
  *
  * Converts rxq context from sparse to dense structure and then writes
- * it to HW register space
+ * it to HW register space and enables the hardware to prefetch descriptors
+ * instead of only fetching them on demand
  */
 enum ice_status
 ice_write_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx *rlan_ctx,
@@ -1231,6 +1233,11 @@ ice_write_rxq_ctx(struct ice_hw *hw, struct ice_rlan_ctx 
*rlan_ctx,
 {
        u8 ctx_buf[ICE_RXQ_CTX_SZ] = { 0 };
 
+       if (!rlan_ctx)
+               return ICE_ERR_BAD_PTR;
+
+       rlan_ctx->prefena = 1;
+
        ice_set_ctx((u8 *)rlan_ctx, ctx_buf, ice_rlan_ctx_info);
        return ice_copy_rxq_ctx_to_hw(hw, ctx_buf, rxq_index);
 }
diff --git a/drivers/net/ice/base/ice_lan_tx_rx.h 
b/drivers/net/ice/base/ice_lan_tx_rx.h
index ef12b9f7c..fa2309bf1 100644
--- a/drivers/net/ice/base/ice_lan_tx_rx.h
+++ b/drivers/net/ice/base/ice_lan_tx_rx.h
@@ -807,6 +807,7 @@ struct ice_rlan_ctx {
        u8 tphdata_ena;
        u8 tphhead_ena;
        u16 lrxqthresh; /* bigger than needed, see above for reason */
+       u8 prefena;     /* NOTE: normally must be set to 1 at init */
 };
 
 struct ice_ctx_ele {
-- 
2.17.1