ethernet jumbo frame

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vcher
Posts: 4
Joined: Sun Jun 30, 2019 11:26 am

ethernet jumbo frame

Sun Jun 30, 2019 11:37 am

Hi!

we work with ATSAMA5D2C-XULT reference board according to the manual it must support jumbo packets
but we cannot change MTU size more thank 1500 .we burned latest linux.
PLease explain what we need to to add jumbo packets support
Do we need special linux build to allow it?
please help us to find out!
Thanks
Vladimir
blue_z
Location: USA
Posts: 1978
Joined: Thu Apr 19, 2007 10:15 pm

Re: ethernet jumbo frame

Tue Jul 02, 2019 12:57 am

Among the Microchip/Atmel family of SoCs, jumbo frames has only been enabled in recent Linux kernels for the Gigabit Ethernet MAC of the SAMA5D3.
For other SoCs that use the Cadence macb driver, a patch similar to the SAMA5D3 patch would be needed to enable jumbo frames.

Regards
vcher
Posts: 4
Joined: Sun Jun 30, 2019 11:26 am

Re: ethernet jumbo frame

Wed Jul 03, 2019 9:49 am

hi!

i have build new image with the patch i can change mtu size but when i ping with size
like
ping 10.0.0.10 -s 3000 not working
please help to find out i see driver and harware is support jumbo

i have changed

static const struct macb_config sama5d2_config = {
.caps = MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII,
.dma_burst_length = 16,
.clk_init = macb_clk_init,
.init = macb_init,
.pm = &macb_sama5d2_pm,
}


to ....

static const struct macb_config sama5d2_config = {
.caps = MACB_CAPS_SG_DISABLED | MACB_CAPS_GIGABIT_MODE_AVAILABLE
| MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII | MACB_CAPS_JUMBO,
.dma_burst_length = 16,
.clk_init = macb_clk_init,
.init = macb_init,
.jumbo_max_len = 10240,
.pm = &macb_sama5d2_pm,
};
vcher
Posts: 4
Joined: Sun Jun 30, 2019 11:26 am

Re: ethernet jumbo frame

Wed Jul 03, 2019 9:57 am

hi!
i have build a linux image with the patch
i have changed next sama5d2_config i can change MTU size but when i ping with size ping 10.0.0.10 -s 3000
i dont dont see in wireshark packet > 1500
i see cadence macb supports jumbo and sama5d2 hardware is also support it
please help me to find out what is going in?

static const struct macb_config sama5d2_config = {
.caps = MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII,
.dma_burst_length = 16,
.clk_init = macb_clk_init,
.init = macb_init,
.pm = &macb_sama5d2_pm,
};
................
to jumbo config

static const struct macb_config sama5d2_config = {
.caps = MACB_CAPS_SG_DISABLED | MACB_CAPS_GIGABIT_MODE_AVAILABLE
| MACB_CAPS_USRIO_DEFAULT_IS_MII_GMII | MACB_CAPS_JUMBO,
.dma_burst_length = 16,
.clk_init = macb_clk_init,
.init = macb_init,
.jumbo_max_len = 10240,
.pm = &macb_sama5d2_pm,
};
vcher
Posts: 4
Joined: Sun Jun 30, 2019 11:26 am

Re: ethernet jumbo frame

Wed Jul 03, 2019 10:23 am

hi!
i just check the max MTU is working its 1900 bytes
please explain why i cannot to get more
thanks
blue_z
Location: USA
Posts: 1978
Joined: Thu Apr 19, 2007 10:15 pm

Re: ethernet jumbo frame

Fri Jul 12, 2019 2:31 am

vcher wrote: please explain why i cannot to get more
You did not patch the driver correctly.
The SAMA5D3 patch simply appends the "| MACB_CAPS_JUMBO" string to the capabilities (.caps), and inserts a new line (".jumbo_max_len = 10240,").
You did not make such modifications to the driver for the SAMA5D2.
Instead you made the SAMA5D2 capabilities to be identical to the SAMA5D3 capabilities .
That makes no sense at all (e.g. the SAMA5D2 GMAC, despite its name, is not capable of Gigabit mode), nor should you expect that to work.

Regards

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