Messages in this thread Patches in this message | | | Subject | Re: Kernel Panic in skb_release_data using genet | From | Florian Fainelli <> | Date | Thu, 10 Jun 2021 14:33:17 -0700 |
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On 6/2/2021 6:28 AM, Maxime Ripard wrote: > On Tue, Jun 01, 2021 at 11:33:18AM +0200, nicolas saenz julienne wrote: >> On Mon, 2021-05-31 at 19:36 -0700, Florian Fainelli wrote: >>>> That is also how I boot my Pi4 at home, and I suspect you are right, if >>>> the VPU does not shut down GENET's DMA, and leaves buffer addresses in >>>> the on-chip descriptors that point to an address space that is managed >>>> totally differently by Linux, then we can have a serious problem and >>>> create some memory corruption when the ring is being reclaimed. I will >>>> run a few experiments to test that theory and there may be a solution >>>> using the SW_INIT reset controller to have a big reset of the controller >>>> before handing it over to the Linux driver. >>> >>> Adding a WARN_ON(reg & DMA_EN) in bcmgenet_dma_disable() has not shown >>> that the TX or RX DMA have been left running during the hand over from >>> the VPU to the kernel. I checked out drm-misc-next-2021-05-17 to reduce >>> as much as possible the differences between your set-up and my set-up >>> but so far have not been able to reproduce the crash in booting from NFS >>> repeatedly, I will try again. >> >> FWIW I can reproduce the error too. That said it's rather hard to reproduce, >> something in the order of 1 failure every 20 tries. > > Yeah, it looks like it's only from a cold boot and comes in "bursts", > where you would get like 5 in a row and be done with it for a while.
Here are two patches that you could try exclusive from one another
1) Limit GENET to a single queue
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index fcca023f22e5..e400c12e6868 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -3652,6 +3652,12 @@ static int bcmgenet_change_carrier(struct net_device *dev, bool new_carrier) return 0; }
+static u16 bcmgenet_select_queue(struct net_device *dev, struct sk_buff *skb, + struct net_device *sb_dev) +{ + return 0; +} + static const struct net_device_ops bcmgenet_netdev_ops = { .ndo_open = bcmgenet_open, .ndo_stop = bcmgenet_close, @@ -3666,6 +3672,7 @@ static const struct net_device_ops bcmgenet_netdev_ops = { #endif .ndo_get_stats = bcmgenet_get_stats, .ndo_change_carrier = bcmgenet_change_carrier, + .ndo_select_queue = bcmgenet_select_queue, };
/* Array of GENET hardware parameters/characteristics */ 2) Ensure that all TX/RX queues are disabled upon DMA initialization
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index fcca023f22e5..7f8a5996fbbb 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -3237,15 +3237,21 @@ static void bcmgenet_get_hw_addr(struct bcmgenet_priv *priv, /* Returns a reusable dma control register value */ static u32 bcmgenet_dma_disable(struct bcmgenet_priv *priv) { + unsigned int i; u32 reg; u32 dma_ctrl;
/* disable DMA */ dma_ctrl = 1 << (DESC_INDEX + DMA_RING_BUF_EN_SHIFT) | DMA_EN; + for (i = 0; i < priv->hw_params->tx_queues; i++) + dma_ctrl |= (1 << (i + DMA_RING_BUF_EN_SHIFT)); reg = bcmgenet_tdma_readl(priv, DMA_CTRL); reg &= ~dma_ctrl; bcmgenet_tdma_writel(priv, reg, DMA_CTRL);
+ dma_ctrl = 1 << (DESC_INDEX + DMA_RING_BUF_EN_SHIFT) | DMA_EN; + for (i = 0; i < priv->hw_params->rx_queues; i++) + dma_ctrl |= (1 << (i + DMA_RING_BUF_EN_SHIFT)); reg = bcmgenet_rdma_readl(priv, DMA_CTRL); reg &= ~dma_ctrl; bcmgenet_rdma_writel(priv, reg, DMA_CTRL); -- Florian
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