[PATCH v2 05/10] common/cnxk: always use single interrupt ID with NIX

[Nithin Dabilpuram]

From: Harman Kalra <hkalra at marvell.com>

An errata exists whereby, in certain cases NIX may use an
incorrect QINT_IDX for SQ interrupts. As a result, the
interrupt may not be delivered to software, or may not be
associated with the correct SQ.
When NIX uses an incorrect QINT_IDX :
1. NIX_LF_QINT(0..63)_CNT[COUNT] will be incremented for
incorrect QINT.
2. NIX_LF_QINT(0..63)_INT[INTR] will be set for incorrect
QINT.

Signed-off-by: Harman Kalra <hkalra at marvell.com>
Acked-by: Jerin Jacob <jerinj at marvell.com>
---
 drivers/common/cnxk/roc_nix_queue.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/common/cnxk/roc_nix_queue.c b/drivers/common/cnxk/roc_nix_queue.c
index c638cd4..80e1c9f 100644
--- a/drivers/common/cnxk/roc_nix_queue.c
+++ b/drivers/common/cnxk/roc_nix_queue.c
@@ -690,7 +690,11 @@ sq_cn9k_init(struct nix *nix, struct roc_nix_sq *sq, uint32_t rr_quantum,
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_MNQ_ERR);
 
 	/* Many to one reduction */
-	aq->sq.qint_idx = sq->qid % nix->qints;
+	/* Assigning QINT 0 to all the SQs, an errata exists where NIXTX can
+	 * send incorrect QINT_IDX when reporting queue interrupt (QINT). This
+	 * might result in software missing the interrupt.
+	 */
+	aq->sq.qint_idx = 0;
 }
 
 static int
@@ -789,8 +793,11 @@ sq_init(struct nix *nix, struct roc_nix_sq *sq, uint32_t rr_quantum,
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_SEND_ERR);
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_MNQ_ERR);
 
-	/* Many to one reduction */
-	aq->sq.qint_idx = sq->qid % nix->qints;
+	/* Assigning QINT 0 to all the SQs, an errata exists where NIXTX can
+	 * send incorrect QINT_IDX when reporting queue interrupt (QINT). This
+	 * might result in software missing the interrupt.
+	 */
+	aq->sq.qint_idx = 0;
 }
 
 static int
-- 
2.8.4