From: Vignesh Raghavendra vigneshr@ti.com
[ Upstream commit 47bfc4d128dedd9e828e33b70b87b591a6d59edf ]
On TI K3 am64x platform the issue with RX IRQ is observed - it's become disabled forever after .ndo_stop(). The K3 CPSW driver manipulates RX IRQ by using standard Linux enable_irq()/disable_irq_nosync() API as there is no IRQ enable/disable options in CPSW HW itself, as result during .ndo_stop() following sequence happens
phy_stop() teardown TX/RX channels wait for TX tdown complete napi_disable(TX) clean up TX channels
(a)
napi_disable(RX)
At point (a) it's not possible to predict if RX IRQ was triggered or not. if RX IRQ was triggered then it also not possible to definitely say if RX NAPI was run or only scheduled and immediately canceled by napi_disable(RX). Actually the last case causes RX IRQ to be permanently disabled.
Another observed issue is that RX IRQ enable counter become unbalanced if (gro_flush_timeout =! 0) while (napi_defer_hard_irqs == 0):
Unbalanced enable for IRQ 44 WARNING: CPU: 0 PID: 10 at ../kernel/irq/manage.c:776 __enable_irq+0x38/0x80 __enable_irq+0x38/0x80 enable_irq+0x54/0xb0 am65_cpsw_nuss_rx_poll+0x2f4/0x368 __napi_poll+0x34/0x1b8 net_rx_action+0xe4/0x220 _stext+0x11c/0x284 run_ksoftirqd+0x4c/0x60
To avoid above issues introduce flag indicating if RX was actually disabled before enabling it in am65_cpsw_nuss_rx_poll() and restore RX IRQ state in .ndo_open()
Fixes: 4f7cce272403 ("net: ethernet: ti: am65-cpsw: add support for am64x cpsw3g") Signed-off-by: Vignesh Raghavendra vigneshr@ti.com Signed-off-by: Grygorii Strashko grygorii.strashko@ti.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ti/am65-cpsw-nuss.c | 13 +++++++++++-- drivers/net/ethernet/ti/am65-cpsw-nuss.h | 2 ++ 2 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c index fb58fc470773..e967cd1ade36 100644 --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c @@ -518,6 +518,10 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common, }
napi_enable(&common->napi_rx); + if (common->rx_irq_disabled) { + common->rx_irq_disabled = false; + enable_irq(common->rx_chns.irq); + }
dev_dbg(common->dev, "cpsw_nuss started\n"); return 0; @@ -871,8 +875,12 @@ static int am65_cpsw_nuss_rx_poll(struct napi_struct *napi_rx, int budget)
dev_dbg(common->dev, "%s num_rx:%d %d\n", __func__, num_rx, budget);
- if (num_rx < budget && napi_complete_done(napi_rx, num_rx)) - enable_irq(common->rx_chns.irq); + if (num_rx < budget && napi_complete_done(napi_rx, num_rx)) { + if (common->rx_irq_disabled) { + common->rx_irq_disabled = false; + enable_irq(common->rx_chns.irq); + } + }
return num_rx; } @@ -1090,6 +1098,7 @@ static irqreturn_t am65_cpsw_nuss_rx_irq(int irq, void *dev_id) { struct am65_cpsw_common *common = dev_id;
+ common->rx_irq_disabled = true; disable_irq_nosync(irq); napi_schedule(&common->napi_rx);
diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.h b/drivers/net/ethernet/ti/am65-cpsw-nuss.h index 5d93e346f05e..048ed10143c1 100644 --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.h +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.h @@ -126,6 +126,8 @@ struct am65_cpsw_common { struct am65_cpsw_rx_chn rx_chns; struct napi_struct napi_rx;
+ bool rx_irq_disabled; + u32 nuss_ver; u32 cpsw_ver; unsigned long bus_freq;