There is network regression for me. 4.18 was good. 4.18+ is bad. There was some phy changes in r8169 driver. Fortunately adding CONFIG_REALTEK_PHY=m to kernel config fixed the regression.
Should r8169 depend on realtek_phy? Does that breaks something else? Network doesn't work with Generic PHY (output of dmesg) Generic PHY r8169-300:00: attached PHY driver [Generic PHY] (mii_bus:phy_addr=r8169-300:00, irq=IGNORE) When realtek_phy is compiled, r8169 automatically uses it. RTL8211B Gigabit Ethernet r8169-300:00: attached PHY driver [RTL8211B Gigabit Ethernet] (mii_bus:phy_addr=r8169-300:00, irq=IGNORE) Here is Ethernet controller's lspci for reference: 03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 01) Subsystem: ABIT Computer Corp. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [147b:1078] Flags: bus master, fast devsel, latency 0, IRQ 27 I/O ports at ce00 [size=256] Memory at fddff000 (64-bit, non-prefetchable) [size=4K] [virtual] Expansion ROM at fdd00000 [disabled] [size=64K] Capabilities: [40] Power Management version 2 Capabilities: [48] Vital Product Data Capabilities: [50] MSI: Enable+ Count=1/2 Maskable- 64bit+ Capabilities: [60] Express Endpoint, MSI 00 Capabilities: [84] Vendor Specific Information: Len=4c <?> Capabilities: [100] Advanced Error Reporting Capabilities: [12c] Virtual Channel Capabilities: [148] Device Serial Number 28-00-00-00-00-00-00- 00 Capabilities: [154] Power Budgeting <?> Kernel driver in use: r8169 Kernel modules: r8169