Re: [PATCH net-next v5 13/13] ax88796b: Add support for AX88772D, AX88179A and AX88279

On 06/08/2026 23:16, Andrew Lunn wrote:
>>>> +static int asix_ax88279_config_aneg(struct phy_device *phydev)
>>>> +{
>>>> +	bool adv_2500;
>>>> +	int ret;
>>>> +
>>>> +	if (phydev->autoneg == AUTONEG_DISABLE) {
>>>> +		phydev_warn(phydev, "Disabling autoneg is not supported\n");
>>>> +		return -EINVAL;
>>>> +	}
>>>
>>> Why is that? Now that phylink is driving the PHY, and reporting
>>> speeds, duplex etc, you should have everything you need to program the
>>> MAC when the link mode is forced.
>>>
>> I tried forcing the PHY speed in the past, and it does not work.
>> This is a limitation which is also acknowledged for the suspected underlying PHY
>> hardware Airoha EN8811H, see the head of air_en8811h.c
> 
> How well does this unwind on error? Is phydev->autoneg put back to the
> old state to indicate autoneg is used?
> 
> This is one of the areas where phylib/phylink is missing a bit of
> support infrastructure. We have a bit indicating the PHY support
> autoneg, ETHTOOL_LINK_MODE_Autoneg_BIT, but there is no bit
> ETHTOOL_LINK_MODE_Force_BIT, indicating the PHY supports forced
> mode. So the core cannot enforce this and reject it in
> ksettings_set().
The error is handled quite poorly:
$ sudo ethtool -s enx6c6e07090000 autoneg off speed 1000
$ ip a
shows link is down

Kernel log:
[848763.836126] Asix Electronics AX88279 usb-004:045:03: Disabling autoneg is not supported
[848763.836134] ------------[ cut here ]------------
[848763.836137] _phy_start_aneg+0x0/0xa0: returned: -22
[848763.836142] WARNING: drivers/net/phy/phy.c:1352 at _phy_state_machine+0x100/0x310, CPU#8: kworker/8:1/534588
[848763.836146] Modules linked in: ax88179_178a cdc_mbim cdc_ncm ax88179(OE) ax88796b(OE) cdc_ether phylink(OE) r8152 nfnetlink_queue nfnetlink_log cdc_wdm usbnet mii sd_mod scsi_mod scsi_common 
snd_seq_dummy snd_hrtimer snd_seq snd_seq_device ccm qrtr rfcomm algif_hash algif_skcipher af_alg bnep binfmt_misc nls_ascii nls_cp437 vfat fat amd_atl snd_acp_legacy_mach snd_acp_mach intel_rapl_msr 
snd_soc_nau8821 intel_rapl_common snd_acp3x_rn snd_soc_dmic snd_acp3x_pdm_dma snd_sof_amd_rembrandt snd_sof_amd_acp snd_sof_pci snd_sof_xtensa_dsp snd_sof snd_sof_utils snd_pci_ps edac_mce_amd iwlmvm 
snd_soc_acpi_amd_match snd_soc_acpi_amd_sdca_quirks snd_amd_sdw_acpi kvm_amd soundwire_amd btusb soundwire_generic_allocation btmtk mac80211 soundwire_bus btrtl kvm snd_soc_sdca snd_hda_codec_conexant 
btbcm snd_hda_codec_generic btintel snd_hda_codec_atihdmi snd_soc_core snd_hda_codec_hdmi snd_compress snd_hda_intel snd_pcm_dmaengine libarc4 irqbypass snd_hda_codec aesni_intel snd_acp_pci bluetooth 
snd_ctl_led gf128mul snd_amd_acpi_mach
[848763.836238]  iwlwifi snd_hda_core snd_acp_legacy_common think_lmi rapl snd_intel_dspcfg snd_pci_acp6x ecdh_generic snd_intel_sdw_acpi snd_pci_acp5x firmware_attributes_class wmi_bmof pcspkr 
snd_hwdep thinkpad_acpi cfg80211 snd_pcm nvram snd_rn_pci_acp3x snd_timer sparse_keymap snd_acp_config ee1004 snd snd_soc_acpi ccp k10temp snd_pci_acp3x rfkill ac soundcore amd_pmc joydev uvcvideo 
evdev videobuf2_vmalloc uvc videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc msr i2c_dev ecryptfs parport_pc ppdev lp dm_mod parport efi_pstore configfs nfnetlink efivarfs ip_tables 
x_tables autofs4 ext4 mbcache jbd2 crc32c_cryptoapi amdgpu drm_buddy amdxcp drm_panel_backlight_quirks gpu_sched drm_ttm_helper ttm drm_exec i2c_algo_bit drm_suballoc_helper drm_display_helper 
hid_multitouch cec hid_generic ucsi_acpi typec_ucsi rc_core nvme xhci_pci i2c_hid_acpi typec i2c_hid drm_client_lib sp5100_tco xhci_hcd roles hid drm_kms_helper psmouse r8169 watchdog nvme_core video 
thunderbolt usbcore i2c_piix4 realtek nvme_keyring
[848763.836342]  serio_raw drm nvme_auth phy_package crc16 i2c_smbus usb_common wmi battery button [last unloaded: ax88796b(OE)]
[848763.836359] CPU: 8 UID: 0 PID: 534588 Comm: kworker/8:1 Tainted: G  R     W  OE       7.1.3+deb13-amd64 #1 PREEMPT(lazy)  Debian 7.1.3-1~bpo13+1
[848763.836365] Tainted: [R]=FORCED_RMMOD, [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
[848763.836367] Hardware name: LENOVO 21JR005UGE/21JR005UGE, BIOS R2CET38W(1.20 ) 07/29/2024
[848763.836371] Workqueue: events_power_efficient phy_state_machine
[848763.836374] RIP: 0010:_phy_state_machine+0x102/0x310
[848763.836377] Code: 00 00 00 48 89 df 41 bc 01 00 00 00 e8 87 f8 ff ff 48 c7 c6 c0 63 1b 9b 83 f8 ed 74 79 85 c0 79 46 48 8d 3d 60 7a 7b 01 89 c2 <67> 48 0f b9 3a 48 8d bb 68 05 00 00 e8 2d dc 65 ff 
84 c0 0f 84 a7
[848763.836380] RSP: 0018:ffffd18e8baebe18 EFLAGS: 00010282
[848763.836383] RAX: 00000000ffffffea RBX: ffff88d4e0359800 RCX: 0000000000000000
[848763.836386] RDX: 00000000ffffffea RSI: ffffffff9b1b63c0 RDI: ffffffff9c96e5b0
[848763.836387] RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
[848763.836390] R10: 727463656c452078 R11: 656c452078697341 R12: 0000000000000001
[848763.836391] R13: ffff88d442ec9b80 R14: ffff88d4e0359d10 R15: 0000000000000000
[848763.836393] FS:  0000000000000000(0000) GS:ffff88d801d16000(0000) knlGS:0000000000000000
[848763.836396] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[848763.836398] CR2: 00007f20af9bd943 CR3: 000000023bd5a000 CR4: 0000000000f50ef0
[848763.836400] PKRU: 55555554
[848763.836402] Call Trace:
[848763.836405]  <TASK>
[848763.836411]  phy_state_machine+0x28/0x50
[848763.836415]  process_one_work+0x198/0x390
[848763.836421]  worker_thread+0x1af/0x320
[848763.836425]  ? __pfx_worker_thread+0x10/0x10
[848763.836429]  kthread+0xe3/0x120
[848763.836432]  ? __pfx_kthread+0x10/0x10
[848763.836435]  ret_from_fork+0x2ba/0x340
[848763.836439]  ? __pfx_kthread+0x10/0x10
[848763.836442]  ret_from_fork_asm+0x1a/0x30
[848763.836449]  </TASK>
[848763.836451] ---[ end trace 0000000000000000 ]---
[848763.836458] ax88179 4-1:1.0 enx6c6e07090000: phy link down 2500base-x/1Gbps/Full/none/rx/tx/nolpi
[848763.836489] ax88179 4-1:1.0 enx6c6e07090000: Link is Down
[848764.571154] r8152 4-2:1.0 enx00e04c680000: carrier off


$ sudo ethtool -s enx6c6e07090000 autoneg on
Does not recover.

Birger