From: Joakim Zhang <qiangqing.zhang@xxxxxxx> commit b5bd95d17102b6719e3531d627875b9690371383 upstream. Background: We have a customer is running a Profinet stack on the 8MM which receives and responds PNIO packets every 4ms and PNIO-CM packets every 40ms. However, from time to time the received PNIO-CM package is "stock" and is only handled when receiving a new PNIO-CM or DCERPC-Ping packet (tcpdump shows the PNIO-CM and the DCERPC-Ping packet at the same time but the PNIO-CM HW timestamp is from the expected 40 ms and not the 2s delay of the DCERPC-Ping). After debugging, we noticed PNIO, PNIO-CM and DCERPC-Ping packets would be handled by different RX queues. The root cause should be driver ack all queues' interrupt when handle a specific queue in fec_enet_rx_queue(). The blamed patch is introduced to receive as much packets as possible once to avoid interrupt flooding. But it's unreasonable to clear other queues'interrupt when handling one queue, this patch tries to fix it. Fixes: ed63f1dcd578 (net: fec: clear receive interrupts before processing a packet) Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> Reported-by: Nicolas Diaz <nicolas.diaz@xxxxxxx> Signed-off-by: Joakim Zhang <qiangqing.zhang@xxxxxxx> Link: https://lore.kernel.org/r/20211206135457.15946-1-qiangqing.zhang@xxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/freescale/fec.h | 3 +++ drivers/net/ethernet/freescale/fec_main.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -360,6 +360,9 @@ struct bufdesc_ex { #define FEC_ENET_WAKEUP ((uint)0x00020000) /* Wakeup request */ #define FEC_ENET_TXF (FEC_ENET_TXF_0 | FEC_ENET_TXF_1 | FEC_ENET_TXF_2) #define FEC_ENET_RXF (FEC_ENET_RXF_0 | FEC_ENET_RXF_1 | FEC_ENET_RXF_2) +#define FEC_ENET_RXF_GET(X) (((X) == 0) ? FEC_ENET_RXF_0 : \ + (((X) == 1) ? FEC_ENET_RXF_1 : \ + FEC_ENET_RXF_2)) #define FEC_ENET_TS_AVAIL ((uint)0x00010000) #define FEC_ENET_TS_TIMER ((uint)0x00008000) --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1407,7 +1407,7 @@ fec_enet_rx_queue(struct net_device *nde if ((status & BD_ENET_RX_LAST) == 0) netdev_err(ndev, "rcv is not +last\n"); - writel(FEC_ENET_RXF, fep->hwp + FEC_IEVENT); + writel(FEC_ENET_RXF_GET(queue_id), fep->hwp + FEC_IEVENT); /* Check for errors. */ if (status & (BD_ENET_RX_LG | BD_ENET_RX_SH | BD_ENET_RX_NO |
