igc: optimize TX packet buffer utilization for TSN mode

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@intel.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index ec8f926362eb3b77b129ecea1e3f3a5d5e6687fa..5502edd6261f4e00d8951cceeaadb699d9f100cd 100644 (file)
--- 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 */