LS1046A DPAA Jumbo Frame using upstream ethernet driver

[fredericlefranc]

Hello,

I'm using the linux kernel from LSDK_21_08 (kernel 5.10). I choose to use DPAA upstream driver instead of the private one.

Everything is working properly except the fact that I can't change MTU to something bigger than the default 1500.

I've tried to use the max-frame-size property in the device tree for each ethernet, but it doesn't change anything.
It seems that to achieve a higher MTU value, I need to configure frame size in FMAN, but with the upstream driver, I have no way to do that.

Do you guys have a solution to allow jumbo frames on LS1046A using upstream driver?

Side question, what are the advantages/disadvantages of using private driver instead of mainline one?

Regards,
Fred.

[yipingwang]

To enable Jumbo frame, the user is required to set the L2 maximum frame size to 9600, otherwise the configuration is not valid.

This can be achieved by either setting fsl_fm_max_frm=9600 in the bootargs, or configuring CONFIG_FSL_FM_MAX_FRAME_SIZE from menuconfig.

[fredericlefranc]

Hi,

Yes this procedure is the one that should work when using private driver. I choose to use mainline driver, so these are either not available (CONFIG_FSL_FM_MAX_FRAME_SIZE), or doesn't work (fsl_fm_max_frm=9600 in kernel's command line).

I see that I could create a new devicetree value (like max_l2_size) and modify fman driver to use it, but I was wondering why jumbo frame was not available as is in mainline driver.

Regards,
Frederic.

[GregUngerer1]

I am experiencing this same problem with the DPAA/FMAN drivers in the mainline kernel. I am using linux-5.18 kernel. So the problem still exits as far as I can tell.

Federic, did you ever get a solution to fix this on mainline kernels?