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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2011-08-04 17:36:27 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2011-08-04 17:36:27 +0000
commit27818ae52468960526f812b8629043ad72d8c7eb (patch)
treeb54751568f45b9ef4b3feb77b866856dc732039d /target/linux
parent3fe5c4149be89260eb8870c0272d512197b24c99 (diff)
ag71xx: fix memory corruption issues on ar7240 on ethernet start/stop
When the DMA engine state gets corrupted due to a hardware issues, it often won't stop rx until a full reset is issued. In that case the hardware must keep a valid descriptor, otherwise it will write to random places in system RAM, triggering random crashes. To fix this, keep a dummy descriptor without a buffer that keeps the DMA engine in a sane state until the reset is done git-svn-id: svn://svn.openwrt.org/openwrt/trunk@27895 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux')
-rw-r--r--target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx.h3
-rw-r--r--target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c19
2 files changed, 19 insertions, 3 deletions
diff --git a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx.h b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx.h
index 1025bb4c4..9dcbf4a5b 100644
--- a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx.h
+++ b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx.h
@@ -148,6 +148,9 @@ struct ag71xx {
struct napi_struct napi;
u32 msg_enable;
+ struct ag71xx_desc *stop_desc;
+ dma_addr_t stop_desc_dma;
+
struct ag71xx_ring rx_ring;
struct ag71xx_ring tx_ring;
diff --git a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
index 1f9cdf3b7..9bfaa8213 100644
--- a/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ag71xx/ag71xx_main.c
@@ -374,8 +374,8 @@ static void ag71xx_dma_reset(struct ag71xx *ag)
mdelay(1);
/* clear descriptor addresses */
- ag71xx_wr(ag, AG71XX_REG_TX_DESC, 0);
- ag71xx_wr(ag, AG71XX_REG_RX_DESC, 0);
+ ag71xx_wr(ag, AG71XX_REG_TX_DESC, ag->stop_desc_dma);
+ ag71xx_wr(ag, AG71XX_REG_RX_DESC, ag->stop_desc_dma);
/* clear pending RX/TX interrupts */
for (i = 0; i < 256; i++) {
@@ -1085,6 +1085,16 @@ static int __devinit ag71xx_probe(struct platform_device *pdev)
ag->tx_ring.size = AG71XX_TX_RING_SIZE_DEFAULT;
ag->rx_ring.size = AG71XX_RX_RING_SIZE_DEFAULT;
+ ag->stop_desc = dma_alloc_coherent(NULL,
+ sizeof(struct ag71xx_desc), &ag->stop_desc_dma, GFP_KERNEL);
+
+ if (!ag->stop_desc)
+ goto err_free_irq;
+
+ ag->stop_desc->data = 0;
+ ag->stop_desc->ctrl = 0;
+ ag->stop_desc->next = (u32) ag->stop_desc_dma;
+
memcpy(dev->dev_addr, pdata->mac_addr, ETH_ALEN);
netif_napi_add(dev, &ag->napi, ag71xx_poll, AG71XX_NAPI_WEIGHT);
@@ -1092,7 +1102,7 @@ static int __devinit ag71xx_probe(struct platform_device *pdev)
err = register_netdev(dev);
if (err) {
dev_err(&pdev->dev, "unable to register net device\n");
- goto err_free_irq;
+ goto err_free_desc;
}
printk(KERN_INFO "%s: Atheros AG71xx at 0x%08lx, irq %d\n",
@@ -1120,6 +1130,9 @@ err_phy_disconnect:
ag71xx_phy_disconnect(ag);
err_unregister_netdev:
unregister_netdev(dev);
+err_free_desc:
+ dma_free_coherent(NULL, sizeof(struct ag71xx_desc), ag->stop_desc,
+ ag->stop_desc_dma);
err_free_irq:
free_irq(dev->irq, dev);
err_unmap_mii_ctrl: