[PATCH net-next v2 02/11] net: ethernet: qualcomm: ppe: Fix multicast queue config table access

[Luo Jie]

PPE queues 0-255 are unicast queues and queues from 256 onwards are
multicast queues. The multicast queue configuration table has its own
index, starting from 0 for the first multicast queue, and each entry
has 3 words.

The driver uses the absolute queue ID as the index of this table, which
is out of range for every multicast queue. As a result, the multicast
queue thresholds are never configured, and unrelated QM registers are
written instead. The driver also accesses 5 words per entry instead
of 3.

Fix it by converting the queue ID to the index of the multicast queue
configuration table and accessing only the 3 words of the entry.

Signed-off-by: Luo Jie <jie.luo@xxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/qualcomm/ppe/ppe_config.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/ppe/ppe_config.c b/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
index 125b73be92b1..2f4f59280647 100644
--- a/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
+++ b/drivers/net/ethernet/qualcomm/ppe/ppe_config.c
@@ -1474,7 +1474,7 @@ static int ppe_config_qm(struct ppe_device *ppe_dev)
 {
 	const struct ppe_qm_queue_config *queue_cfg;
 	int ret, i, queue_id, queue_cfg_count;
-	u32 reg, multicast_queue_cfg[5];
+	u32 reg, multicast_queue_cfg[3];
 	u32 unicast_queue_cfg[4];
 	u32 group_cfg[3];
 
@@ -1530,8 +1530,13 @@ static int ppe_config_qm(struct ppe_device *ppe_dev)
 				if (ret)
 					goto qm_config_fail;
 			} else {
+				/* The multicast queue table is indexed from 0 for
+				 * the first multicast queue, which follows the
+				 * unicast queues.
+				 */
 				reg = PPE_AC_MULTICAST_QUEUE_CFG_TBL_ADDR +
-				      PPE_AC_MULTICAST_QUEUE_CFG_TBL_INC * queue_id;
+				      PPE_AC_MULTICAST_QUEUE_CFG_TBL_INC *
+				      (queue_id - PPE_AC_UNICAST_QUEUE_CFG_TBL_ENTRIES);
 
 				ret = regmap_bulk_read(ppe_dev->regmap, reg,
 						       multicast_queue_cfg,

-- 
2.43.0