[PATCH 4.4 019/192] [PATCH 019/135] fm10k: Correct MTU for jumbo frames

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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[ Upstream commit 8c7ee6d2cacc7794a91875ef5fd8284b4a900d8c ]

Based on hardware testing, the host interface supports up to 15368 bytes
as the maximum frame size. To determine the correct MTU, we subtract 8
for the internal switch tag, 14 for the L2 header, and 4 for the
appended FCS header, resulting in 15342 bytes of payload for our maximum
MTU on jumbo frames.

Signed-off-by: Matthew Vick <matthew.vick@xxxxxxxxx>
Signed-off-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
Acked-by: Bruce Allan <bruce.w.allan@xxxxxxxxx>
Tested-by: Krishneil Singh <krishneil.k.singh@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/intel/fm10k/fm10k.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/fm10k/fm10k.h
+++ b/drivers/net/ethernet/intel/fm10k/fm10k.h
@@ -33,7 +33,7 @@
 #include "fm10k_pf.h"
 #include "fm10k_vf.h"
 
-#define FM10K_MAX_JUMBO_FRAME_SIZE	15358	/* Maximum supported size 15K */
+#define FM10K_MAX_JUMBO_FRAME_SIZE	15342	/* Maximum supported size 15K */
 
 #define MAX_QUEUES	FM10K_MAX_QUEUES_PF