diff mbox

[03/12] net: axienet: Service completion interrupts ASAP

Message ID 2effdfc484793a74e6f53ee7e1b2ef5cebb2bfe9.1430817941.git.michal.simek@xilinx.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Michal Simek May 5, 2015, 9:25 a.m. UTC 
From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

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 <peter.crosthwaite@xilinx.com>
Tested-by: Jason Wu <huanyu@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

 drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
index a4840952d372..b83425393a24 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;
 }