kern/51211: atactl atabus0 reset causes a panic on Tegra K1

[erik%ono-sendai.com@localhost]

>Number:         51211
>Category:       kern
>Synopsis:       atactl atabus0 reset causes a panic on Tegra K1
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jun 02 03:20:03 +0000 2016
>Originator:     Erik Berls
>Release:        NetBSD armv7 7.99.30 NetBSD 7.99.30 (TEGRA.201606011320Z) evbarm
>Organization:
NetBSD
>Environment:
NetBSD armv7 7.99.30 NetBSD 7.99.30 (TEGRA.201606011320Z) evbarm

Userland from armv7.img.gz

With a SATA Port Multiplier

>Description:

ahcisata0 at fdt0: SATA
ahcisata0: couldn't acquire vddio-supply
ahcisata0: couldn't acquire avdd-supply
ahcisata0: interrupting on LIC irq 55
ahcisata0: AHCI revision 1.31, 2 ports, 32 slots, CAP 0xe620ff01<PSC,SSC,PMD,ISS=0x2=Gen2,SAL,SALP,SSNTF,SNCQ,S64A>
atabus0 at ahcisata0 channel 0
[...]
wd0 at atabus0 drive 0
wd0: <WDC WD1600AAJS-00B4A0>
wd0: 149 GB, 310101 cyl, 16 head, 63 sec, 512 bytes/sect x 312581808 sectors

[...]

armv7# drvctl -r atabus0
drvctl: DRVRESCANBUS: Invalid argument

armv7# atactl atabus0 reset
ahcisata0 port 0: device present, speed: 3.0Gb/s
panic: kernel diagnostic assertion "sc->sc_ahci_cap & AHCI_CAP_CLO" failed: file "/usr/src/sys/dev/ic/ahcisata_core.c", line 1404 
cpu3: Begin traceback...
0x9c7c9c0c: netbsd:db_panic+0xc
0x9c7c9c24: netbsd:vpanic+0x1b4
0x9c7c9c3c: netbsd:__udivmoddi4
0x9c7c9c8c: netbsd:ahci_channel_start+0x250
0x9c7c9cbc: netbsd:ahci_reset_channel+0xd4
0x9c7c9cdc: netbsd:ata_reset_channel+0x64
0x9c7c9d04: netbsd:atabusioctl+0xe4
0x9c7c9d44: netbsd:cdev_ioctl+0xcc
0x9c7c9d6c: netbsd:spec_ioctl+0x94
0x9c7c9d9c: netbsd:VOP_IOCTL+0x4c
0x9c7c9e6c: netbsd:vn_ioctl+0xc4
0x9c7c9f34: netbsd:sys_ioctl+0x1b8
0x9c7c9fac: netbsd:syscall+0x94
cpu3: End traceback...

dump to dev 92,1 not possible
rebooting...

>How-To-Repeat:
JTK1 + SATA PM + trying to rescan the bus (eg after hotswap)

>Fix: