From 80c775accdf834567a8e163eee9a3531eeafea7d Mon Sep 17 00:00:00 2001 From: Peter Crosthwaite Date: Tue, 5 May 2015 11:25:56 +0200 Subject: [PATCH] net: axienet: Service completion interrupts ASAP The packet completion interrupts for TX and RX should be serviced before the packets are consumed. This ensures against the degenerate case when a new completion interrupt is raised after the handler has exited but before the interrupts are cleared. In this case its possible for the ISR to clear an unhandled interrupt (leading to potential deadlock). Signed-off-by: Peter Crosthwaite Tested-by: Jason Wu Acked-by: Michal Simek Signed-off-by: Michal Simek Signed-off-by: David S. Miller --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index a484095..b834253 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -809,6 +809,7 @@ static irqreturn_t axienet_tx_irq(int irq, void *_ndev) status = axienet_dma_in32(lp, XAXIDMA_TX_SR_OFFSET); if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) { + axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status); axienet_start_xmit_done(lp->ndev); goto out; } @@ -832,9 +833,9 @@ static irqreturn_t axienet_tx_irq(int irq, void *_ndev) axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr); tasklet_schedule(&lp->dma_err_tasklet); + axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status); } out: - axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status); return IRQ_HANDLED; } @@ -857,6 +858,7 @@ static irqreturn_t axienet_rx_irq(int irq, void *_ndev) status = axienet_dma_in32(lp, XAXIDMA_RX_SR_OFFSET); if (status & (XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK)) { + axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status); axienet_recv(lp->ndev); goto out; } @@ -880,9 +882,9 @@ static irqreturn_t axienet_rx_irq(int irq, void *_ndev) axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr); tasklet_schedule(&lp->dma_err_tasklet); + axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status); } out: - axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status); return IRQ_HANDLED; } -- 2.7.4