[PATCH 5.7 172/265] net: macb: free resources on failure path of at91ether_open()

Sasha Levin
2020-06-29T21:58:30Z

From: Claudiu Beznea <claudiu.beznea@microchip.com>

[ Upstream commit 33fdef24c9ac20c68b71b363e423fbf9ad2bfc1e ]

DMA buffers were not freed on failure path of at91ether_open().
Along with changes for freeing the DMA buffers the enable/disable
interrupt instructions were moved to at91ether_start()/at91ether_stop()
functions and the operations on at91ether_stop() were done in
their reverse order (compared with how is done in at91ether_start()):
before this patch the operation order on interface open path
was as follows:
1/ alloc DMA buffers
2/ enable tx, rx
3/ enable interrupts
and the order on interface close path was as follows:
1/ disable tx, rx
2/ disable interrupts
3/ free dma buffers.

Fixes: 7897b071ac3b ("net: macb: convert to phylink")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cadence/macb_main.c | 116 ++++++++++++++---------
1 file changed, 73 insertions(+), 43 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 5705359a36124..52582e8ed90e5 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -3762,15 +3762,9 @@ static int macb_init(struct platform_device *pdev)

static struct sifive_fu540_macb_mgmt *mgmt;

-/* Initialize and start the Receiver and Transmit subsystems */
-static int at91ether_start(struct net_device *dev)
+static int at91ether_alloc_coherent(struct macb *lp)
{
- struct macb *lp = netdev_priv(dev);
struct macb_queue *q = &lp->queues[0];
- struct macb_dma_desc *desc;
- dma_addr_t addr;
- u32 ctl;
- int i;

q->rx_ring = dma_alloc_coherent(&lp->pdev->dev,
(AT91ETHER_MAX_RX_DESCR *
@@ -3792,6 +3786,43 @@ static int at91ether_start(struct net_device *dev)
return -ENOMEM;
}

+ return 0;
+}
+
+static void at91ether_free_coherent(struct macb *lp)
+{
+ struct macb_queue *q = &lp->queues[0];
+
+ if (q->rx_ring) {
+ dma_free_coherent(&lp->pdev->dev,
+ AT91ETHER_MAX_RX_DESCR *
+ macb_dma_desc_get_size(lp),
+ q->rx_ring, q->rx_ring_dma);
+ q->rx_ring = NULL;
+ }
+
+ if (q->rx_buffers) {
+ dma_free_coherent(&lp->pdev->dev,
+ AT91ETHER_MAX_RX_DESCR *
+ AT91ETHER_MAX_RBUFF_SZ,
+ q->rx_buffers, q->rx_buffers_dma);
+ q->rx_buffers = NULL;
+ }
+}
+
+/* Initialize and start the Receiver and Transmit subsystems */
+static int at91ether_start(struct macb *lp)
+{
+ struct macb_queue *q = &lp->queues[0];
+ struct macb_dma_desc *desc;
+ dma_addr_t addr;
+ u32 ctl;
+ int i, ret;
+
+ ret = at91ether_alloc_coherent(lp);
+ if (ret)
+ return ret;
+
addr = q->rx_buffers_dma;
for (i = 0; i < AT91ETHER_MAX_RX_DESCR; i++) {
desc = macb_rx_desc(q, i);
@@ -3813,9 +3844,39 @@ static int at91ether_start(struct net_device *dev)
ctl = macb_readl(lp, NCR);
macb_writel(lp, NCR, ctl | MACB_BIT(RE) | MACB_BIT(TE));

+ /* Enable MAC interrupts */
+ macb_writel(lp, IER, MACB_BIT(RCOMP) |
+ MACB_BIT(RXUBR) |
+ MACB_BIT(ISR_TUND) |
+ MACB_BIT(ISR_RLE) |
+ MACB_BIT(TCOMP) |
+ MACB_BIT(ISR_ROVR) |
+ MACB_BIT(HRESP));
+
return 0;
}

+static void at91ether_stop(struct macb *lp)
+{
+ u32 ctl;
+
+ /* Disable MAC interrupts */
+ macb_writel(lp, IDR, MACB_BIT(RCOMP) |
+ MACB_BIT(RXUBR) |
+ MACB_BIT(ISR_TUND) |
+ MACB_BIT(ISR_RLE) |
+ MACB_BIT(TCOMP) |
+ MACB_BIT(ISR_ROVR) |
+ MACB_BIT(HRESP));
+
+ /* Disable Receiver and Transmitter */
+ ctl = macb_readl(lp, NCR);
+ macb_writel(lp, NCR, ctl & ~(MACB_BIT(TE) | MACB_BIT(RE)));
+
+ /* Free resources. */
+ at91ether_free_coherent(lp);
+}
+
/* Open the ethernet interface */
static int at91ether_open(struct net_device *dev)
{
@@ -3835,27 +3896,20 @@ static int at91ether_open(struct net_device *dev)

macb_set_hwaddr(lp);

- ret = at91ether_start(dev);
+ ret = at91ether_start(lp);
if (ret)
goto pm_exit;

- /* Enable MAC interrupts */
- macb_writel(lp, IER, MACB_BIT(RCOMP) |
- MACB_BIT(RXUBR) |
- MACB_BIT(ISR_TUND) |
- MACB_BIT(ISR_RLE) |
- MACB_BIT(TCOMP) |
- MACB_BIT(ISR_ROVR) |
- MACB_BIT(HRESP));
-
ret = macb_phylink_connect(lp);
if (ret)
- goto pm_exit;
+ goto stop;

netif_start_queue(dev);

return 0;

+stop:
+ at91ether_stop(lp);
pm_exit:
pm_runtime_put_sync(&lp->pdev->dev);
return ret;
@@ -3865,37 +3919,13 @@ pm_exit:
static int at91ether_close(struct net_device *dev)
{
struct macb *lp = netdev_priv(dev);
- struct macb_queue *q = &lp->queues[0];
- u32 ctl;
-
- /* Disable Receiver and Transmitter */
- ctl = macb_readl(lp, NCR);
- macb_writel(lp, NCR, ctl & ~(MACB_BIT(TE) | MACB_BIT(RE)));
-
- /* Disable MAC interrupts */
- macb_writel(lp, IDR, MACB_BIT(RCOMP) |
- MACB_BIT(RXUBR) |
- MACB_BIT(ISR_TUND) |
- MACB_BIT(ISR_RLE) |
- MACB_BIT(TCOMP) |
- MACB_BIT(ISR_ROVR) |
- MACB_BIT(HRESP));

netif_stop_queue(dev);

phylink_stop(lp->phylink);
phylink_disconnect_phy(lp->phylink);

- dma_free_coherent(&lp->pdev->dev,
- AT91ETHER_MAX_RX_DESCR *
- macb_dma_desc_get_size(lp),
- q->rx_ring, q->rx_ring_dma);
- q->rx_ring = NULL;
-
- dma_free_coherent(&lp->pdev->dev,
- AT91ETHER_MAX_RX_DESCR * AT91ETHER_MAX_RBUFF_SZ,
- q->rx_buffers, q->rx_buffers_dma);
- q->rx_buffers = NULL;
+ at91ether_stop(lp);

return pm_runtime_put(&lp->pdev->dev);
}
--
2.25.1