[PATCH net v2] net: airoha: Wait for NPU PPE configuration to complete in airoha_ppe_offload_setup()

[Lorenzo Bianconi <lorenzo@kernel.org>]

In order to properly enable flowtable hw offloading, poll
REG_PPE_FLOW_CFG register in airoha_ppe_offload_setup routine and
wait for NPU PPE configuration triggered by ppe_init callback to complete
before running airoha_ppe_hw_init().

Fixes: 00a7678310fe3 ("net: airoha: Introduce flowtable offload support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
Changes in v2:
- Check for both REG_PPE_PPE_FLOW_CFG(0) and REG_PPE_PPE_FLOW_CFG(1) to
  complete.
- Link to v1: https://lore.kernel.org/r/20260412-airoha-wait-for-npu-config-offload-setup-v1-1-f4e0aa2a5d85@kernel.org
---
 drivers/net/ethernet/airoha/airoha_ppe.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/net/ethernet/airoha/airoha_ppe.c b/drivers/net/ethernet/airoha/airoha_ppe.c
index 62cfffb4f0e5..684c8ae9576f 100644
--- a/drivers/net/ethernet/airoha/airoha_ppe.c
+++ b/drivers/net/ethernet/airoha/airoha_ppe.c
@@ -1335,6 +1335,29 @@ static struct airoha_npu *airoha_ppe_npu_get(struct airoha_eth *eth)
 	return npu;
 }
 
+static int airoha_ppe_wait_for_npu_init(struct airoha_eth *eth)
+{
+	int err;
+	u32 val;
+
+	/* PPE_FLOW_CFG default register value is 0. Since we reset FE
+	 * during the device probe we can just check the configured value
+	 * is not 0 here.
+	 */
+	err = read_poll_timeout(airoha_fe_rr, val, val, USEC_PER_MSEC,
+				100 * USEC_PER_MSEC, false, eth,
+				REG_PPE_PPE_FLOW_CFG(0));
+	if (err)
+		return err;
+
+	if (airoha_ppe_is_enabled(eth, 1))
+		err = read_poll_timeout(airoha_fe_rr, val, val, USEC_PER_MSEC,
+					100 * USEC_PER_MSEC, false, eth,
+					REG_PPE_PPE_FLOW_CFG(1));
+
+	return err;
+}
+
 static int airoha_ppe_offload_setup(struct airoha_eth *eth)
 {
 	struct airoha_npu *npu = airoha_ppe_npu_get(eth);
@@ -1348,6 +1371,11 @@ static int airoha_ppe_offload_setup(struct airoha_eth *eth)
 	if (err)
 		goto error_npu_put;
 
+	/* Wait for NPU PPE configuration to complete */
+	err = airoha_ppe_wait_for_npu_init(eth);
+	if (err)
+		goto error_npu_put;
+
 	ppe_num_stats_entries = airoha_ppe_get_total_num_stats_entries(ppe);
 	if (ppe_num_stats_entries > 0) {
 		err = npu->ops.ppe_init_stats(npu, ppe->foe_stats_dma,

---
base-commit: b9d8b856689d2b968495d79fe653d87fcb8ad98c
change-id: 20260412-airoha-wait-for-npu-config-offload-setup-19d04522412d

Best regards,
-- 
Lorenzo Bianconi <lorenzo@kernel.org>