jme: Fix unmap error (Causing system freeze) (94c5b41b) · Commits · 戴 / test

This patch add the missing dma_unmap(). Which solved the critical issue of system freeze on heavy load. Michal Miroslaw's rejected patch: [PATCH v2 10/46] net: jme: convert to generic DMA API Pointed out the issue also, thank you Michal. But the fix was incorrect. It would unmap needed address when low memory. Got lots of feedback from End user and Gentoo Bugzilla. https://bugs.gentoo.org/show_bug.cgi?id=373109 Thank you all. :) Cc: stable@kernel.org Signed-off-by:

Guo-Fu Tseng <cooldavid@cooldavid.org> Acked-by:

Chris Wright <chrisw@sous-sol.org> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/jme.c

+14 −6

Original line number	Diff line number	Diff line
		@@ -753,20 +753,28 @@ jme_make_new_rx_buf(struct jme_adapter *jme, int i)
		struct jme_ring *rxring = &(jme->rxring[0]);
		struct jme_buffer_info *rxbi = rxring->bufinf + i;
		struct sk_buff *skb;
		dma_addr_t mapping;

		skb = netdev_alloc_skb(jme->dev,
		jme->dev->mtu + RX_EXTRA_LEN);
		if (unlikely(!skb))
		return -ENOMEM;

		rxbi->skb = skb;
		rxbi->len = skb_tailroom(skb);
		rxbi->mapping = pci_map_page(jme->pdev,
		virt_to_page(skb->data),
		offset_in_page(skb->data),
		rxbi->len,
		mapping = pci_map_page(jme->pdev, virt_to_page(skb->data),
		offset_in_page(skb->data), skb_tailroom(skb),
		PCI_DMA_FROMDEVICE);
		if (unlikely(pci_dma_mapping_error(jme->pdev, mapping))) {
		dev_kfree_skb(skb);
		return -ENOMEM;
		}

		if (likely(rxbi->mapping))
		pci_unmap_page(jme->pdev, rxbi->mapping,
		rxbi->len, PCI_DMA_FROMDEVICE);

		rxbi->skb = skb;
		rxbi->len = skb_tailroom(skb);
		rxbi->mapping = mapping;
		return 0;
		}

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