Hi Marek,
On 1/30/2026 2:26 AM, Marek Vasut wrote:
> On 1/30/26 1:29 AM, Jonas Karlman wrote:
>> The commit 05278af8b3df ("eth: asix88179: packet drop when receiving
>> large fragmented packets") adjusted the URB buffer size to allow large
>> fragmented packets. However, this change result in use of a large URB
>> buffer size for slow speed connections, e.g. 10/100M use 26 KiB.
>>
>> Using a ASIX AX88179B USB 3.0 or ASIX AX88772E USB 2.0 Ethernet adapter
>> on a Rockchip RK3528 with a DWC2 USB controller this large URB buffer
>> size result in invalid rx_hdr and result in unusable Ethernet.
>>
>> The data read back from AX_RX_BULKIN_QCTRL after being configured also
>> does not match the values in the AX88179_BULKIN_SIZE array.
>>
>> Change to use a fixed URB buffer size of 16 KiB to fix use of Ethernet,
>
> Why 16 kiB and not something else ?
Using anything larger than 16 KiB resulted in issues, and a datasheet
for the older AX88772 prior to the D revision mention default 16 KiB for
"Maximum Frame Burst transfer on USB bus" so 16 KiB seemed like a safe
size to use for newer revisions, and this also made it possible to use
fragmented packets up to just below 16 KiB.
>
> Is this a USB controller related problem/limitation ? Maybe the DWC2
> driver needs fixing instead, to handler larger buffers ?
I accidentally mixed up what host controller was being used, the board in
question is using a generic-echi controller not the DWC2 as I stated.
Below follow some debug prints, what can be observed is that when
length=26624 is returned from ehci_submit_bulk_msg the ax88179_eth_recv
will return len >16 KiB and that result in the rx_hdr at the end of
the returned buffer being bogus data, e.g. for following:
BOOTP broadcast 1
** asix_send_common(), len 342
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0680, length=350,
req=0000000000000000
TOKEN=0x80008c00
Tx: len = 346, actual = 350, err = 0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7808d00
ax88179_eth_recv: second try, len=16512
ax88179_eth_recv: 2 packets received, pkt header at 112
ax88179_eth_recv: return packet of 106 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
The buffers returned from the AX88179 contains something like:
<packet data N><N+1>... <packet header N><N+1>... <RX HDR>
Above the "2 packets received, pkt header at 112" seem to indicate that
the pkt header is in the middle of the packet data, in other instances
the rx_hdr seem to indicate that the buffer contains thousands of
packets, i.e. the rx_hdr is likely bogus when more than 16 KiB is
returned from ehci_submit_bulk_msg.
More info and debug prints:
=> dm tree -e usb
Class Seq Probed Driver Name
-----------------------------------------------------------
pinconfig 277 [ + ] pinconfig usb
pinconfig 278 [ + ] pinconfig `-- usb-host-en
pinconfig 280 [ ] pinconfig usb-wifi-pwr
nop 0 [ ] dwc3-generic-wrapper usb@fe500000
usb_gadget 0 [ ] dwc3-generic-periphe `-- usb@fe500000
usb 0 [ + ] ehci_generic usb@ff100000
usb_hub 0 [ + ] usb_hub `-- usb_hub
usb_hub 1 [ + ] usb_hub `-- usb_hub
ethernet 0 [ + ] ax88179_eth `-- ax88179_eth
bootdev 2 [ + ] eth_bootdev `--
ax88179_eth.bootdev
nop 1 [ + ] rockchip_usb2phy usb2phy@ffdf0000
phy 1 [ ] rockchip_usb2phy_por |-- otg-port
phy 2 [ + ] rockchip_usb2phy_por |-- host-port
clk 3 [ + ] rockchip_usb2phy_clo `-- clk_usbphy_480m
=> usb tree
USB device tree:
1 Hub (480 Mb/s, 0mA)
| u-boot EHCI Host Controller
|
+-2 Hub (480 Mb/s, 100mA)
| USB 2.0 Hub
|
+-3 Vendor specific (480 Mb/s, 100mA)
| ASIX AX88772E 00CFCE77
|
=> dhcp
** asix_init_common()
asix_write_cmd() cmd=0x01 value=0x000b index=0x0002 size=2
usb_control_msg: request: 0x1, requesttype: 0x40, value 0xB index 0x2 length 0x2
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000303, buffer=00000000f9ee0bc0, length=2,
req=00000000f9ee0ac0
req=1 (0x1), type=64 (0x40), value=11 (0xb), index=2
TOKEN=0x8d01
asix_read_cmd() cmd=0x02 value=0x0003 index=0x0001 size=2
usb_control_msg: request: 0x2, requesttype: 0xC0, value 0x3 index 0x1 length 0x2
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000383, buffer=00000000f9ee0b80, length=2,
req=00000000f9ee0a80
req=2 (0x2), type=192 (0xc0), value=3 (0x3), index=1
TOKEN=0x8c00
asix_read_cmd() cmd=0x01 value=0x0002 index=0x0001 size=1
usb_control_msg: request: 0x1, requesttype: 0xC0, value 0x2 index 0x1 length 0x1
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000383, buffer=00000000f9ee0bc0, length=1,
req=00000000f9ee0ac0
req=1 (0x1), type=192 (0xc0), value=2 (0x2), index=1
TOKEN=0x8c00
asix_read_cmd() cmd=0x02 value=0x0003 index=0x0011 size=2
usb_control_msg: request: 0x2, requesttype: 0xC0, value 0x3 index 0x11 length
0x2
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000383, buffer=00000000f9ee0bc0, length=2,
req=00000000f9ee0ac0
req=2 (0x2), type=192 (0xc0), value=3 (0x3), index=17
TOKEN=0x8c00
asix_write_cmd() cmd=0x01 value=0x002e index=0x0005 size=5
usb_control_msg: request: 0x1, requesttype: 0x40, value 0x2E index 0x5 length
0x5
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000303, buffer=00000000f9ee0bc0, length=5,
req=00000000f9ee0ac0
req=1 (0x1), type=64 (0x40), value=46 (0x2e), index=5
TOKEN=0x8d01
asix_write_cmd() cmd=0x01 value=0x0022 index=0x0002 size=2
usb_control_msg: request: 0x1, requesttype: 0x40, value 0x22 index 0x2 length
0x2
ehci_submit_control_msg: dev='usb@ff100000', udev=00000000f9f2c520,
udev->dev='ax88179_eth', portnr=3
dev=00000000f9f2c520, pipe=80000303, buffer=00000000f9ee0bc0, length=2,
req=00000000f9ee0ac0
req=1 (0x1), type=64 (0x40), value=34 (0x22), index=2
TOKEN=0x8d01
BOOTP broadcast 1
** asix_send_common(), len 342
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0680, length=350,
req=0000000000000000
TOKEN=0x80008c00
Tx: len = 346, actual = 350, err = 0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7808d00
ax88179_eth_recv: second try, len=16512
ax88179_eth_recv: 2 packets received, pkt header at 112
ax88179_eth_recv: return packet of 106 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
BOOTP broadcast 2
** asix_send_common(), len 342
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0680, length=350,
req=0000000000000000
TOKEN=0x8c00
Tx: len = 346, actual = 350, err = 0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x27808d00
ax88179_eth_recv: second try, len=16512
ax88179_eth_recv: 2 packets received, pkt header at 112
ax88179_eth_recv: return packet of 106 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
BOOTP broadcast 3
** asix_send_common(), len 342
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0680, length=350,
req=0000000000000000
TOKEN=0x80008c00
Tx: len = 346, actual = 350, err = 0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7a88d00
ax88179_eth_recv: second try, len=16472
ax88179_eth_recv: 2 packets received, pkt header at 72
ax88179_eth_recv: return packet of 3938 bytes (1 packets left)
** asix_send_common(), len 342
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0600, length=350,
req=0000000000000000
TOKEN=0x8c00
Tx: len = 346, actual = 350, err = 0
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x27a88d00
ax88179_eth_recv: second try, len=16472
ax88179_eth_recv: 2 packets received, pkt header at 72
ax88179_eth_recv: return packet of 3938 bytes (1 packets left)
DHCP client bound to address 192.168.42.234 (3365 ms)
Using ax88179_eth device
TFTP from server 192.168.2.50; our IP address is 192.168.42.234; sending
through gateway 192.168.42.1
Filename 'default'.
Load address: 0xc00800
Loading: ** asix_send_common(), len 42
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0580, length=50,
req=0000000000000000
TOKEN=0x80008c00
Tx: len = 46, actual = 50, err = 0
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7988d00
ax88179_eth_recv: second try, len=16488
ax88179_eth_recv: 2 packets received, pkt header at 88
ax88179_eth_recv: return packet of 0 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x27a88d00
ax88179_eth_recv: second try, len=16472
ax88179_eth_recv: 2 packets received, pkt header at 72
ax88179_eth_recv: return packet of 3650 bytes (1 packets left)
ax88179_eth_recv: return packet of 4949 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7808d00
ax88179_eth_recv: second try, len=16512
ax88179_eth_recv: 2 packets received, pkt header at 112
ax88179_eth_recv: return packet of 106 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x26189d00
ax88179_eth_recv: second try, len=16872
ax88179_eth_recv: 2 packets received, pkt header at 472
ax88179_eth_recv: return packet of 0 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7b08d00
ax88179_eth_recv: second try, len=16464
ax88179_eth_recv: 2 packets received, pkt header at 64
ax88179_eth_recv: return packet of 3360 bytes (1 packets left)
ax88179_eth_recv: return packet of 0 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x27b08d00
ax88179_eth_recv: second try, len=16464
ax88179_eth_recv: 2 packets received, pkt header at 64
ax88179_eth_recv: return packet of 5681 bytes (1 packets left)
ax88179_eth_recv: return packet of 3141 bytes (0 packets left)
ax88179_eth_recv: first try, len=0
** asix_send_common(), len 42
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0680, length=50,
req=0000000000000000
TOKEN=0x8c00
Tx: len = 46, actual = 50, err = 0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0xa7a88d00
ax88179_eth_recv: second try, len=16472
ax88179_eth_recv: 2 packets received, pkt header at 72
ax88179_eth_recv: return packet of 0 bytes (1 packets left)
ax88179_eth_recv: return packet of 64 bytes (0 packets left)
** asix_send_common(), len 82
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0018303, buffer=00000000f9ee0600, length=90,
req=0000000000000000
TOKEN=0x80008c00
Tx: len = 86, actual = 90, err = 0
ax88179_eth_recv: first try, len=0
ax88179_eth_recv: first try, len=0
ehci_submit_bulk_msg: dev='usb@ff100000', udev=00000000f9f2c520
dev=00000000f9f2c520, pipe=c0010383, buffer=00000000f9f2cf00, length=26624,
req=0000000000000000
TOKEN=0x27b08d00
ax88179_eth_recv: second try, len=16464
ax88179_eth_recv: 2 packets received, pkt header at 64
ax88179_eth_recv: return packet of 63 bytes (1 packets left)
TFTP error: 'File not found' (1)
Not retrying...
** ax88179_eth_stop()
Regards,
Jonas
