If the NIC reports that there is a computed CRC appended to the frame
content, we need to subtract its size from the total length before
passing that further down the network stack.
This fixes a WARN_ON_ONCE reported by the network stack when built
with #define DEBUG, because the expected size as indicated by the IP
header is not the same as what's reported by the driver.
Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
drivers/net/cpsw.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/cpsw.c b/drivers/net/cpsw.c
index 31ca61a230e9..3aafebaad49d 100644
--- a/drivers/net/cpsw.c
+++ b/drivers/net/cpsw.c
@@ -51,10 +51,12 @@
#define CPDMA_DESC_EOP BIT(30)
#define CPDMA_DESC_OWNER BIT(29)
#define CPDMA_DESC_EOQ BIT(28)
+#define CPDMA_DESC_PASS_CRC BIT(26)
#define CPDMA_DESC_TO_PORT_EN BIT(20)
#define CPDMA_FROM_TO_PORT_SHIFT 16
#define CPDMA_RX_SOURCE_PORT(__status__) \
(((__status__) >> CPDMA_FROM_TO_PORT_SHIFT) & 0x7)
+#define CPDMA_DESC_CRC_LEN 4
#define SLIVER_SIZE 0x40
@@ -865,8 +867,11 @@ static int cpdma_process(struct cpsw_slave *slave, struct cpdma_chan *chan,
status = readl(&desc->hw_mode);
- if (len)
+ if (len) {
*len = status & 0x7ff;
+ if (status & CPDMA_DESC_PASS_CRC)
+ *len -= CPDMA_DESC_CRC_LEN;
+ }
if (dma)
*dma = readl(&desc->hw_buffer);
--
2.39.2
