The receive frame length calculation uses a wrong mask to calculate the
length of the received frames.
Per spec table 4-1 the length is contained in the FL (Frame Length)
field in bits 30:16.
This didn't show up as an issue so far since frames were limited to
1500 bytes which falls within the 11 bit window.
Signed-off-by: Moritz Fischer <mdf@xxxxxxxxxx>
---
drivers/net/ethernet/dec/tulip/de2104x.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/dec/tulip/de2104x.c b/drivers/net/ethernet/dec/tulip/de2104x.c
index d305d1b24b0a..42b798a3fad4 100644
--- a/drivers/net/ethernet/dec/tulip/de2104x.c
+++ b/drivers/net/ethernet/dec/tulip/de2104x.c
@@ -417,7 +417,10 @@ static void de_rx (struct de_private *de)
if (status & DescOwn)
break;
- len = ((status >> 16) & 0x7ff) - 4;
+ /* the length is actually a 15 bit value here according
+ * to Table 4-1 in the DE2104x spec so mask is 0x7fff
+ */
+ len = ((status >> 16) & 0x7fff) - 4;
mapping = de->rx_skb[rx_tail].mapping;
if (unlikely(drop)) {
--
2.25.0
