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Documentation: networking: update stmmac

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Update stmmac driver documentation according to new GMAC 4.x family.

Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexandre TORGUE 2016-04-01 11:37:35 +02:00 committed by David S. Miller
parent f748be531d
commit 0b7a43d376
1 changed files with 38 additions and 6 deletions
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44
Documentation/networking/stmmac.txt
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@ -1,6 +1,6 @@
STMicroelectronics 10/100/1000 Synopsys Ethernet driver STMicroelectronics 10/100/1000 Synopsys Ethernet driver
Copyright (C) 2007-2014 STMicroelectronics Ltd Copyright (C) 2007-2015 STMicroelectronics Ltd
Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers
@ -138,6 +138,8 @@ struct plat_stmmacenet_data {
int (*init)(struct platform_device *pdev, void *priv); int (*init)(struct platform_device *pdev, void *priv);
void (*exit)(struct platform_device *pdev, void *priv); void (*exit)(struct platform_device *pdev, void *priv);
void *bsp_priv; void *bsp_priv;
int has_gmac4;
bool tso_en;
}; };
Where: Where:
@ -181,6 +183,8 @@ Where:
registers. init/exit callbacks should not use or modify registers. init/exit callbacks should not use or modify
platform data. platform data.
o bsp_priv: another private pointer. o bsp_priv: another private pointer.
o has_gmac4: uses GMAC4 core.
o tso_en: Enables TSO (TCP Segmentation Offload) feature.
For MDIO bus The we have: For MDIO bus The we have:
@ -278,6 +282,13 @@ Please see the following document:
o stmmac_ethtool.c: to implement the ethtool support; o stmmac_ethtool.c: to implement the ethtool support;
o stmmac.h: private driver structure; o stmmac.h: private driver structure;
o common.h: common definitions and VFTs; o common.h: common definitions and VFTs;
o mmc_core.c/mmc.h: Management MAC Counters;
o stmmac_hwtstamp.c: HW timestamp support for PTP;
o stmmac_ptp.c: PTP 1588 clock;
o dwmac-<XXX>.c: these are for the platform glue-logic file; e.g. dwmac-sti.c
for STMicroelectronics SoCs.
- GMAC 3.x
o descs.h: descriptor structure definitions; o descs.h: descriptor structure definitions;
o dwmac1000_core.c: dwmac GiGa core functions; o dwmac1000_core.c: dwmac GiGa core functions;
o dwmac1000_dma.c: dma functions for the GMAC chip; o dwmac1000_dma.c: dma functions for the GMAC chip;
@ -289,11 +300,32 @@ Please see the following document:
o enh_desc.c: functions for handling enhanced descriptors; o enh_desc.c: functions for handling enhanced descriptors;
o norm_desc.c: functions for handling normal descriptors; o norm_desc.c: functions for handling normal descriptors;
o chain_mode.c/ring_mode.c:: functions to manage RING/CHAINED modes; o chain_mode.c/ring_mode.c:: functions to manage RING/CHAINED modes;
o mmc_core.c/mmc.h: Management MAC Counters;
o stmmac_hwtstamp.c: HW timestamp support for PTP; - GMAC4.x generation
o stmmac_ptp.c: PTP 1588 clock; o dwmac4_core.c: dwmac GMAC4.x core functions;
o dwmac-<XXX>.c: these are for the platform glue-logic file; e.g. dwmac-sti.c o dwmac4_desc.c: functions for handling GMAC4.x descriptors;
for STMicroelectronics SoCs. o dwmac4_descs.h: descriptor definitions;
o dwmac4_dma.c: dma functions for the GMAC4.x chip;
o dwmac4_dma.h: dma definitions for the GMAC4.x chip;
o dwmac4.h: core definitions for the GMAC4.x chip;
o dwmac4_lib.c: generic GMAC4.x functions;
4.12) TSO support (GMAC4.x)
TSO (Tcp Segmentation Offload) feature is supported by GMAC 4.x chip family.
When a packet is sent through TCP protocol, the TCP stack ensures that
the SKB provided to the low level driver (stmmac in our case) matches with
the maximum frame len (IP header + TCP header + payload <= 1500 bytes (for
MTU set to 1500)). It means that if an application using TCP want to send a
packet which will have a length (after adding headers) > 1514 the packet
will be split in several TCP packets: The data payload is split and headers
(TCP/IP ..) are added. It is done by software.
When TSO is enabled, the TCP stack doesn't care about the maximum frame
length and provide SKB packet to stmmac as it is. The GMAC IP will have to
perform the segmentation by it self to match with maximum frame length.
This feature can be enabled in device tree through "snps,tso" entry.
5) Debug Information 5) Debug Information