aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/net/wireless/p54/p54spi.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/net/wireless/p54/p54spi.c b/drivers/net/wireless/p54/p54spi.c
index e830a2e6845..40aeb4387dc 100644
--- a/drivers/net/wireless/p54/p54spi.c
+++ b/drivers/net/wireless/p54/p54spi.c
@@ -371,32 +371,44 @@ static int p54spi_rx(struct p54s_priv *priv)
{
struct sk_buff *skb;
u16 len;
+ u16 rx_head[2];
+#define READAHEAD_SZ (sizeof(rx_head)-sizeof(u16))
if (p54spi_wakeup(priv) < 0)
return -EBUSY;
- /* dummy read to flush SPI DMA controller bug */
- p54spi_read16(priv, SPI_ADRS_GEN_PURP_1);
-
- len = p54spi_read16(priv, SPI_ADRS_DMA_DATA);
+ /* Read data size and first data word in one SPI transaction
+ * This is workaround for firmware/DMA bug,
+ * when first data word gets lost under high load.
+ */
+ p54spi_spi_read(priv, SPI_ADRS_DMA_DATA, rx_head, sizeof(rx_head));
+ len = rx_head[0];
if (len == 0) {
- dev_err(&priv->spi->dev, "rx request of zero bytes");
+ p54spi_sleep(priv);
+ dev_err(&priv->spi->dev, "rx request of zero bytes\n");
return 0;
}
-
/* Firmware may insert up to 4 padding bytes after the lmac header,
* but it does not amend the size of SPI data transfer.
* Such packets has correct data size in header, thus referencing
* past the end of allocated skb. Reserve extra 4 bytes for this case */
skb = dev_alloc_skb(len + 4);
if (!skb) {
+ p54spi_sleep(priv);
dev_err(&priv->spi->dev, "could not alloc skb");
- return 0;
+ return -ENOMEM;
}
- p54spi_spi_read(priv, SPI_ADRS_DMA_DATA, skb_put(skb, len), len);
+ if (len <= READAHEAD_SZ) {
+ memcpy(skb_put(skb, len), rx_head + 1, len);
+ } else {
+ memcpy(skb_put(skb, READAHEAD_SZ), rx_head + 1, READAHEAD_SZ);
+ p54spi_spi_read(priv, SPI_ADRS_DMA_DATA,
+ skb_put(skb, len - READAHEAD_SZ),
+ len - READAHEAD_SZ);
+ }
p54spi_sleep(priv);
/* Put additional bytes to compensate for the possible
* alignment-caused truncation */