When BIOS SATA is set for AHCI mode chipset can see nearby networks but can't connect. When BIOS SATA setting is set to Compatibility then it works in a degraded mode from dhclient buffer issues to ath_edma errors, and 47% packet loss when ping is used. Here are some errors:

ath0: ath_edma_rxbuf_alloc: nothing on rxbuf?!
ath0: ath_edma_rxfifo_alloc: Q1: alloc failed: i=0, nbufs=128?
ath0: ath_edma_recv_proc_queue: Q1: NULL bf?

ath0: ath_edma_recv_tasklet: sc_inreset_cnt > 0; skipping
dhclient[1001]: send_packet: Invalid argument
dhclient[1001]: send_packet: No buffer space available
ath0: ath_edma_recv_tasklet: sc_inreset_cnt > 0; skipping
dhclient[1001]: send_packet: No buffer space available
dhclient[1001]: send_packet: Invalid argument
dhclient[1001]: send_packet: Network is down

pciconf -lv:

hostb0@pci0:0:0:0:    class=0x060000 card=0xfa401179 chip=0x0c048086
rev=0x06 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Haswell DRAM Controller'
    class      = bridge
    subclass   = HOST-PCI
pcib1@pci0:0:1:0:    class=0x060400 card=0xfa471179 chip=0x0c018086
rev=0x06 hdr=0x01
    vendor     = 'Intel Corporation'
    device     = 'Haswell PCI Express x16 Controller'
    class      = bridge
    subclass   = PCI-PCI
vgapci1@pci0:0:2:0:    class=0x030000 card=0xfa471179 chip=0x04168086
rev=0x06 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Haswell Integrated Graphics Controller'
    class      = display
    subclass   = VGA
hdac0@pci0:0:3:0:    class=0x040300 card=0xfa4d1179 chip=0x0c0c8086
rev=0x06 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Haswell HD Audio Controller'
    class      = multimedia
    subclass   = HDA
xhci0@pci0:0:20:0:    class=0x0c0330 card=0xfa401179 chip=0x8c318086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point USB xHCI Host Controller'
    class      = serial bus
    subclass   = USB
none0@pci0:0:22:0:    class=0x078000 card=0xfa401179 chip=0x8c3a8086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point MEI Controller'
    class      = simple comms
ehci0@pci0:0:26:0:    class=0x0c0320 card=0xfa401179 chip=0x8c2d8086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point USB Enhanced Host Controller'
    class      = serial bus
    subclass   = USB
hdac1@pci0:0:27:0:    class=0x040300 card=0xfa4d1179 chip=0x8c208086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point High Definition Audio Controller'
    class      = multimedia
    subclass   = HDA
pcib2@pci0:0:28:0:    class=0x060400 card=0xfa401179 chip=0x8c108086
rev=0xd4 hdr=0x01
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point PCI Express Root Port'
    class      = bridge
    subclass   = PCI-PCI
pcib3@pci0:0:28:2:    class=0x060400 card=0xfa401179 chip=0x8c148086
rev=0xd4 hdr=0x01
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point PCI Express Root Port'
    class      = bridge
    subclass   = PCI-PCI
pcib4@pci0:0:28:3:    class=0x060400 card=0xfa401179 chip=0x8c168086
rev=0xd4 hdr=0x01
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point PCI Express Root Port'
    class      = bridge
    subclass   = PCI-PCI
ehci1@pci0:0:29:0:    class=0x0c0320 card=0xfa401179 chip=0x8c268086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point USB Enhanced Host Controller'
    class      = serial bus
    subclass   = USB
isab0@pci0:0:31:0:    class=0x060100 card=0xfa401179 chip=0x8c498086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point LPC Controller'
    class      = bridge
    subclass   = PCI-ISA
none1@pci0:0:31:3:    class=0x0c0500 card=0xfa401179 chip=0x8c228086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point SMBus Controller'
    class      = serial bus
    subclass   = SMBus
atapci0@pci0:0:31:5:    class=0x010185 card=0xfa401179 chip=0x8c098086
rev=0x04 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Lynx Point 2-port SATA Controller 2 [IDE mode]'
    class      = mass storage
    subclass   = ATA
vgapci0@pci0:1:0:0:    class=0x030200 card=0xfa471179 chip=0x129210de
rev=0xa1 hdr=0x00
    vendor     = 'NVIDIA Corporation'
    class      = display
    subclass   = 3D
ath0@pci0:3:0:0:    class=0x028000 card=0x061211ad chip=0x0036168c
rev=0x01 hdr=0x00
    vendor     = 'Atheros Communications Inc.'
    device     = 'AR9565 Wireless Network Adapter'
    class      = network
none2@pci0:4:0:0:    class=0x020000 card=0xfa401179 chip=0x10a11969
rev=0x10 hdr=0x00
    vendor     = 'Atheros Communications Inc.'
    class      = network
    subclass   = ethernet