[PATCH net-next 07/14] igc: optimize TX packet buffer utilization for TSN mode

[Tony Nguyen]

From: Faizal Rahim <faizal.abdul.rahim at linux.intel.com>

In preparation for upcoming frame preemption patches, optimize the TX
packet buffer size. The total packet buffer size (RX + TX) is 64KB, with
a maximum of 34KB for either RX or TX. Split the buffer evenly,
allocating 32KB to each.

For TX, assign 7KB to each of the four TX packet buffers (total 28KB)
and reserve 4KB for BMC.

References:
I225/I226 SW User Manual Section 4.7.9, Section 8.3.2

Co-developed-by: Vinicius Costa Gomes <vinicius.gomes at intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes at intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim at linux.intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay at intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen at intel.com>
---
 drivers/net/ethernet/intel/igc/igc_defines.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index ec8f926362eb..5502edd6261f 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -419,8 +419,8 @@
 	IGC_TXPB0SIZE(20) | IGC_TXPB1SIZE(0) | IGC_TXPB2SIZE(0) | \
 	IGC_TXPB3SIZE(0) | IGC_OS2BMCPBSIZE(4))
 #define IGC_TXPBSIZE_TSN ( \
-	IGC_TXPB0SIZE(5) | IGC_TXPB1SIZE(5) | IGC_TXPB2SIZE(5) | \
-	IGC_TXPB3SIZE(5) | IGC_OS2BMCPBSIZE(4))
+	IGC_TXPB0SIZE(7) | IGC_TXPB1SIZE(7) | IGC_TXPB2SIZE(7) | \
+	IGC_TXPB3SIZE(7) | IGC_OS2BMCPBSIZE(4))
 
 #define IGC_DTXMXPKTSZ_TSN	0x19 /* 1600 bytes of max TX DMA packet size */
 #define IGC_DTXMXPKTSZ_DEFAULT	0x98 /* 9728-byte Jumbo frames */
-- 
2.47.1