2013-02-13 13:27:17

by Stanislaw Gruszka

[permalink] [raw]
Subject: [PATCH] rt2x00: check for dma mappings errors

Check output of dma_map_single functions which nowadays can fail (when
IOMMU is used). On write_beacon callbacks just print error, similar
like padding error is handled by rt2800_write_beacon.

Signed-off-by: Stanislaw Gruszka <[email protected]>
---
drivers/net/wireless/rt2x00/rt2400pci.c | 12 +++++++++---
drivers/net/wireless/rt2x00/rt2500pci.c | 7 +++++--
drivers/net/wireless/rt2x00/rt2x00.h | 4 +++-
drivers/net/wireless/rt2x00/rt2x00queue.c | 26 +++++++++++++++++++-------
4 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index a2d2bc2..221beaa 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1185,8 +1185,14 @@ static void rt2400pci_write_beacon(struct queue_entry *entry,
rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);
rt2x00pci_register_write(rt2x00dev, CSR14, reg);

- rt2x00queue_map_txskb(entry);
-
+ if (rt2x00queue_map_txskb(entry)) {
+ ERROR(rt2x00dev, "Fail to map beacon, aborting\n");
+ goto out;
+ }
+ /*
+ * Enable beaconing again.
+ */
+ rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 1);
/*
* Write the TX descriptor for the beacon.
*/
@@ -1196,7 +1202,7 @@ static void rt2400pci_write_beacon(struct queue_entry *entry,
* Dump beacon to userspace through debugfs.
*/
rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_BEACON, entry->skb);
-
+out:
/*
* Enable beaconing again.
*/
diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c
index 9bea10f..39edc59 100644
--- a/drivers/net/wireless/rt2x00/rt2500pci.c
+++ b/drivers/net/wireless/rt2x00/rt2500pci.c
@@ -1338,7 +1338,10 @@ static void rt2500pci_write_beacon(struct queue_entry *entry,
rt2x00_set_field32(&reg, CSR14_BEACON_GEN, 0);
rt2x00pci_register_write(rt2x00dev, CSR14, reg);

- rt2x00queue_map_txskb(entry);
+ if (rt2x00queue_map_txskb(entry)) {
+ ERROR(rt2x00dev, "Fail to map beacon, aborting\n");
+ goto out;
+ }

/*
* Write the TX descriptor for the beacon.
@@ -1349,7 +1352,7 @@ static void rt2500pci_write_beacon(struct queue_entry *entry,
* Dump beacon to userspace through debugfs.
*/
rt2x00debug_dump_frame(rt2x00dev, DUMP_FRAME_BEACON, entry->skb);
-
+out:
/*
* Enable beaconing again.
*/
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 9a3f31a..086abb4 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -1169,8 +1169,10 @@ static inline bool rt2x00_is_soc(struct rt2x00_dev *rt2x00dev)
/**
* rt2x00queue_map_txskb - Map a skb into DMA for TX purposes.
* @entry: Pointer to &struct queue_entry
+ *
+ * Returns -ENOMEM if mapping fail, 0 otherwise.
*/
-void rt2x00queue_map_txskb(struct queue_entry *entry);
+int rt2x00queue_map_txskb(struct queue_entry *entry);

/**
* rt2x00queue_unmap_skb - Unmap a skb from DMA.
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index f35d85a..e26ec9d 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -87,24 +87,35 @@ struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry, gfp_t gfp)
skbdesc->entry = entry;

if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags)) {
- skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
- skb->data,
- skb->len,
- DMA_FROM_DEVICE);
+ dma_addr_t skb_dma;
+
+ skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
+ DMA_FROM_DEVICE);
+ if (unlikely(dma_mapping_error(rt2x00dev->dev, skb_dma))) {
+ dev_kfree_skb_any(skb);
+ return NULL;
+ }
+
+ skbdesc->skb_dma = skb_dma;
skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
}

return skb;
}

-void rt2x00queue_map_txskb(struct queue_entry *entry)
+int rt2x00queue_map_txskb(struct queue_entry *entry)
{
struct device *dev = entry->queue->rt2x00dev->dev;
struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);

skbdesc->skb_dma =
dma_map_single(dev, entry->skb->data, entry->skb->len, DMA_TO_DEVICE);
+
+ if (unlikely(dma_mapping_error(dev, skbdesc->skb_dma)))
+ return -ENOMEM;
+
skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
+ return 0;
}
EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);

@@ -545,8 +556,9 @@ static int rt2x00queue_write_tx_data(struct queue_entry *entry,
/*
* Map the skb to DMA.
*/
- if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags))
- rt2x00queue_map_txskb(entry);
+ if (test_bit(REQUIRE_DMA, &rt2x00dev->cap_flags) &&
+ rt2x00queue_map_txskb(entry))
+ return -ENOMEM;

return 0;
}
--
1.7.11.7