Hi, Vladimir,

Which usb2lan driver you are using for AX88772 adpater? The one in 
OptionRomPkg\Bus\Usb\UsbNetworking has bug on the polling performance. The one 
in OptionRomPkg\Bus\Usb\UsbNetworking\Ax88772b is better but if there is no 
data received, the polling operation still wastes some time.

The root cause about the low performance of polling is because USB spec doesn't 
clearly define which value should be returned if user requests Bulk Read 
operation but there is no data. Some data-streaming usb devices, such as 
Realtek usb2lan, return success with data length setting to 0, but others, such 
as AX88772, just keep active and wait for data always. From BIOS view, we have 
to return EFI_TIMEOUT for latter case to avoid system hang. That's why you see 
the low performance for polling operation in no-data case. 

Thanks
Feng

-----Original Message-----
From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Vladimir 
Olovyannikov
Sent: Saturday, April 8, 2017 3:06 AM
To: edk2-devel@lists.01.org
Subject: [edk2] Using USB-Ethernet adapter in UEFI on an arm64 platform

Hi,

I would like to enable Ethernet using USB-Ethernet AX88772 adapter in the UEFI 
on an armv8 arm64 platform.
Ethernet polling is done by MnpPoll() periodically. This creates a burden on 
the system so that UEFI boots in 1 minute to the Shell due to receive polling.
The USB operation is very resource expensive which causes UEFI to choke up.
There is DisableBackgroundPolling option in the EFI_MANAGED_NETWORK_CONFIG_DATA 
structure, but it is turned off by all other drivers (DNSDxe, Ip4Dxe, 
ArpDxe...).
Can anybody advise what I could do?
Mass storage/keyboard/etc. all work fine...

Thank you,
Vladimir
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel

Reply via email to