diff options
| -rw-r--r-- | drivers/net/wireless/p54/p54spi.c | 28 |
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 */ |