[PATCH v3 net-next 1/1] drivers: net: davinci_cpdma: acknowledge interrupt properly

[Mugunthan V N]

CPDMA interrupts are not properly acknowledged which leads to interrupt
storm, only cpdma interrupt 0 is acknowledged in Davinci CPDMA driver.
Changed cpdma_ctlr_eoi api to acknowledge 1 and 2 interrupts which are
used for rx and tx respectively.

Reported-by: Pantelis Antoniou <panto at antoniou-consulting.com>
Signed-off-by: Mugunthan V N <mugunthanvnm at ti.com>
---
Changes from v2:
* Changed the hardware register values from enumeration to defines

 drivers/net/ethernet/ti/cpsw.c          |   25 ++++++++++++++++---------
 drivers/net/ethernet/ti/davinci_cpdma.c |    4 ++--
 drivers/net/ethernet/ti/davinci_cpdma.h |    7 ++++++-
 3 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 4ceed6e..7e93df6 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -510,19 +510,21 @@ static int cpsw_poll(struct napi_struct *napi, int budget)
 	int			num_tx, num_rx;
 
 	num_tx = cpdma_chan_process(priv->txch, 128);
-	num_rx = cpdma_chan_process(priv->rxch, budget);
-
-	if (num_rx || num_tx)
-		cpsw_dbg(priv, intr, "poll %d rx, %d tx pkts\n",
-			 num_rx, num_tx);
+	if (num_tx)
+		cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);
 
+	num_rx = cpdma_chan_process(priv->rxch, budget);
 	if (num_rx < budget) {
 		napi_complete(napi);
 		cpsw_intr_enable(priv);
-		cpdma_ctlr_eoi(priv->dma);
+		cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
 		cpsw_enable_irq(priv);
 	}
 
+	if (num_rx || num_tx)
+		cpsw_dbg(priv, intr, "poll %d rx, %d tx pkts\n",
+			 num_rx, num_tx);
+
 	return num_rx;
 }
 
@@ -835,7 +837,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
 	cpdma_ctlr_start(priv->dma);
 	cpsw_intr_enable(priv);
 	napi_enable(&priv->napi);
-	cpdma_ctlr_eoi(priv->dma);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);
 
 	if (priv->data.dual_emac)
 		priv->slaves[priv->emac_port].open_stat = true;
@@ -1075,7 +1078,9 @@ static void cpsw_ndo_tx_timeout(struct net_device *ndev)
 	cpdma_chan_start(priv->txch);
 	cpdma_ctlr_int_ctrl(priv->dma, true);
 	cpsw_intr_enable(priv);
-	cpdma_ctlr_eoi(priv->dma);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);
+
 }
 
 static struct net_device_stats *cpsw_ndo_get_stats(struct net_device *ndev)
@@ -1094,7 +1099,9 @@ static void cpsw_ndo_poll_controller(struct net_device *ndev)
 	cpsw_interrupt(ndev->irq, priv);
 	cpdma_ctlr_int_ctrl(priv->dma, true);
 	cpsw_intr_enable(priv);
-	cpdma_ctlr_eoi(priv->dma);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
+	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);
+
 }
 #endif
 
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 7d3bffd..68c3418 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -493,9 +493,9 @@ int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable)
 	return 0;
 }
 
-void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr)
+void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value)
 {
-	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, 0);
+	dma_reg_write(ctlr, CPDMA_MACEOIVECTOR, value);
 }
 
 struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
diff --git a/drivers/net/ethernet/ti/davinci_cpdma.h b/drivers/net/ethernet/ti/davinci_cpdma.h
index a97d6ab..d9bcc60 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.h
+++ b/drivers/net/ethernet/ti/davinci_cpdma.h
@@ -26,6 +26,11 @@
 
 #define CPDMA_RX_SOURCE_PORT(__status__)	((__status__ >> 16) & 0x7)
 
+#define CPDMA_EOI_RX_THRESH	0x0
+#define CPDMA_EOI_RX		0x1
+#define CPDMA_EOI_TX		0x2
+#define CPDMA_EOI_MISC		0x3
+
 struct cpdma_params {
 	struct device		*dev;
 	void __iomem		*dmaregs;
@@ -88,7 +93,7 @@ int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data,
 int cpdma_chan_process(struct cpdma_chan *chan, int quota);
 
 int cpdma_ctlr_int_ctrl(struct cpdma_ctlr *ctlr, bool enable);
-void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr);
+void cpdma_ctlr_eoi(struct cpdma_ctlr *ctlr, u32 value);
 int cpdma_chan_int_ctrl(struct cpdma_chan *chan, bool enable);
 bool cpdma_check_free_tx_desc(struct cpdma_chan *chan);
 
-- 
1.7.9.5