target/linux/generic/patches-3.18/077-09-bgmac-increase-rx-ring-size-from-511-to-512.patch

   1 From: Felix Fietkau <nbd@nbd.name>
   2 Date: Sun, 12 Apr 2015 22:36:16 +0200
   3 Subject: [PATCH] bgmac: increase rx ring size from 511 to 512
   4
   5 Limiting it to 511 looks like a failed attempt at leaving one descriptor
   6 empty to allow the hardware to stop processing a buffer that has not
   7 been prepared yet. However, this doesn't work because this affects the
   8 total ring size as well
   9
  10 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  11 ---
  12
  13 --- a/drivers/net/ethernet/broadcom/bgmac.h
  14 +++ b/drivers/net/ethernet/broadcom/bgmac.h
  15 @@ -356,7 +356,7 @@
  16  #define BGMAC_MAX_RX_RINGS                     1
  17
  18  #define BGMAC_TX_RING_SLOTS                    128
  19 -#define BGMAC_RX_RING_SLOTS                    512 - 1         /* Why -1? Well, Broadcom does that... */
  20 +#define BGMAC_RX_RING_SLOTS                    512
  21
  22  #define BGMAC_RX_HEADER_LEN                    28              /* Last 24 bytes are unused. Well... */
  23  #define BGMAC_RX_FRAME_OFFSET                  30              /* There are 2 unused bytes between header and real data */