From 5dab5bf10c848aa900b7651c0dac0c5886b41f76 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sun, 10 Mar 2013 18:25:16 +0000 Subject: cns3xxx: fix an rx irq handling corner case When an rx interrupt comes in, rx interrupts are disabled and NAPI polling is scheduled. During the NAPI poll, the driver first processes received frames in the ring, then fills the dma descriptor slots with new buffers and calls tx complete, before finally re-enabling rx interrupts and completing NAPI (if below the budget). If the hardware rx queue overflows before the napi complete is called, the hardware will not throw any further rx interrupts and rx processing stops completely. Fix this by keeping NAPI polling scheduled until it completes a poll without receiving any packets, and also handle NAPI completion before refilling rx or completing tx. git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35942 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'target/linux/cns3xxx/files/drivers/net/ethernet') diff --git a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c index 7ffff684de..7309d9ea77 100644 --- a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c +++ b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c @@ -706,15 +706,15 @@ static int eth_poll(struct napi_struct *napi, int budget) } } - cns3xxx_alloc_rx_buf(sw, received); - - rx_ring->cur_index = i; - - if (received != budget) { + if (!received) { napi_complete(napi); enable_irq(IRQ_CNS3XXX_SW_R0RXC); } + cns3xxx_alloc_rx_buf(sw, received); + + rx_ring->cur_index = i; + wmb(); enable_rx_dma(sw); -- cgit v1.2.3