airoha_qdma_hw_init() unmasks the per-ring NO_CPU_DSCP interrupt, which fires when an RX ring runs out of free CPU descriptors, but airoha_irq_handler() only extracts the RX_DONE bits from the same status word. The NO_CPU_DSCP bits are acknowledged and dropped. Once a ring is drained to zero posted descriptors no further RX_DONE can fire for it - nothing is left for hw to receive into - so NAPI is never rescheduled, airoha_qdma_fill_rx_queue() is never called again, and the ring stays dead until the interface is reconfigured. This is reachable on RX ring 4, which airoha_fe_vip_setup() force-routes ~15 VIP-classified protocols onto (BOOTP, PPPoE Discovery, ISAKMP, DHCPv6, SIP, LLDP, PPP LCP/IPCP/CHAP/PAP/IPv6CP, ...) while it sits on the 16-descriptor RX_DSCP_NUM() default. A DHCP renewal or a PPPoE negotiation burst drains it faster than the CPU reposts, after which all of those protocols silently stop being received. Treat NO_CPU_DSCP like RX_DONE for scheduling NAPI: airoha_qdma_rx_process() already calls airoha_qdma_fill_rx_queue() unconditionally at the end of every poll, so scheduling NAPI is enough to make an emptied ring refill itself. Re-enable the bit alongside RX_DONE in airoha_qdma_rx_napi_poll() so it is not left masked after first use. Whether NO_CPU_DSCP re-latches while the ring is still empty is not documented. If it does, a ring that cannot be refilled (page_pool returning NULL) keeps reasserting it. Masking it until a refill succeeds is worse: a starved ring never fires RX_DONE either, so it would stay dead after the memory pressure clears. Fixes: f252493e1835 ("net: airoha: Enable multiple IRQ lines support in airoha_eth driver.") Link: https://github.com/openwrt/openwrt/issues/24715 Acked-by: Lorenzo Bianconi Signed-off-by: Vitaliy Sochnev --- drivers/net/ethernet/airoha/airoha_eth.c | 16 +++++++++++----- drivers/net/ethernet/airoha/airoha_regs.h | 2 ++ 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c index 64619e9a704d..c59201aded26 100644 --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -784,13 +784,16 @@ static int airoha_qdma_rx_napi_poll(struct napi_struct *napi, int budget) int i, qid = q - &qdma->q_rx[0]; int intr_reg = qid < RX_DONE_HIGH_OFFSET ? QDMA_INT_REG_IDX1 : QDMA_INT_REG_IDX2; + u32 irq_id = qid % RX_DONE_HIGH_OFFSET; + u32 intr_mask = BIT(irq_id) | + BIT(irq_id + RX_NO_CPU_DSCP_LOW_OFFSET); for (i = 0; i < ARRAY_SIZE(qdma->irq_banks); i++) { if (!(BIT(qid) & RX_IRQ_BANK_PIN_MASK(i))) continue; airoha_qdma_irq_enable(&qdma->irq_banks[i], intr_reg, - BIT(qid % RX_DONE_HIGH_OFFSET)); + intr_mask); } } @@ -1468,16 +1471,19 @@ static irqreturn_t airoha_irq_handler(int irq, void *dev_instance) if (!test_bit(DEV_STATE_INITIALIZED, &qdma->eth->state)) return IRQ_NONE; - rx_intr1 = intr[1] & RX_DONE_LOW_INT_MASK; + rx_intr1 = intr[1] & (RX_DONE_LOW_INT_MASK | RX_NO_CPU_DSCP_LOW_INT_MASK); if (rx_intr1) { airoha_qdma_irq_disable(irq_bank, QDMA_INT_REG_IDX1, rx_intr1); - rx_intr_mask |= rx_intr1; + rx_intr_mask |= (rx_intr1 & RX_DONE_LOW_INT_MASK) | + RX_NO_CPU_DSCP_INT_RX1_MASK(rx_intr1); } - rx_intr2 = intr[2] & RX_DONE_HIGH_INT_MASK; + rx_intr2 = intr[2] & (RX_DONE_HIGH_INT_MASK | RX_NO_CPU_DSCP_HIGH_INT_MASK); if (rx_intr2) { airoha_qdma_irq_disable(irq_bank, QDMA_INT_REG_IDX2, rx_intr2); - rx_intr_mask |= (rx_intr2 << 16); + rx_intr_mask |= ((rx_intr2 & RX_DONE_HIGH_INT_MASK) << + RX_DONE_HIGH_OFFSET) | + (rx_intr2 & RX_NO_CPU_DSCP_HIGH_INT_MASK); } for (i = 0; rx_intr_mask && i < ARRAY_SIZE(qdma->q_rx); i++) { diff --git a/drivers/net/ethernet/airoha/airoha_regs.h b/drivers/net/ethernet/airoha/airoha_regs.h index 442b48c9b991..bde3d599d8b7 100644 --- a/drivers/net/ethernet/airoha/airoha_regs.h +++ b/drivers/net/ethernet/airoha/airoha_regs.h @@ -549,6 +549,8 @@ #define INT_RX1_MASK(_n) \ ((((_n) << RX_NO_CPU_DSCP_LOW_OFFSET) & RX_NO_CPU_DSCP_LOW_INT_MASK) | \ (RX_DONE_LOW_INT_MASK & (_n))) +#define RX_NO_CPU_DSCP_INT_RX1_MASK(_n) \ + (((_n) & RX_NO_CPU_DSCP_LOW_INT_MASK) >> RX_NO_CPU_DSCP_LOW_OFFSET) /* QDMA_CSR_INT_ENABLE3 */ #define RX31_NO_CPU_DSCP_INT_MASK BIT(31) -- 2.55.0