Hi,

I've plugged a SIL3512 SATA-controller into the RB493G to connect a HDD and a SSD. When kmod_ata_sil is installed the SATA ports are detected on boot. After that the kernel segfaults, blocks for a while and then boots normally:

[   10.980000] SCSI subsystem initialized
[   11.070000] PCI: Enabling device 0000:00:12.0 (0000 -> 0002)
[   11.070000] sata_sil 0000:00:12.0: cache line size not set.  Driver may not function
[   11.080000] sata_sil 0000:00:12.0: Applying R_ERR on DMA activate FIS errata fix
[   11.090000] scsi host0: sata_sil
[   11.090000] scsi host1: sata_sil
[   11.100000] ata1: SATA max UDMA/100 mmio m512@0x10080000 tf 0x10080080 irq 40
[   11.100000] ata2: SATA max UDMA/100 mmio m512@0x10080000 tf 0x100800c0 irq 40
[   11.460000] Data bus error, epc == 801a15c4, ra == 8fab25b0
[   11.460000] Oops[#1]:
[   11.460000] CPU: 0 PID: 332 Comm: scsi_eh_0 Not tainted 3.18.23 #1
[   11.460000] task: 8f97ce88 ti: 8fa9a000 task.ti: 8fa9a000
[   11.460000] $ 0   : 00000000 803c0000 000000de b0080084
[   11.460000] $ 4   : b0080084 00000000 8fa9bcf8 00000548
[   11.460000] $ 8   : 8fa9bfe0 0000f400 00000000 ffffff80
[   11.460000] $12   : 0000000e 00000007 00000001 803362c8
[   11.460000] $16   : 8fa08000 b0080000 00000000 8fa08000
[   11.460000] $20   : 8fab5a6c 8fa096d0 8fab5a6c 00000000
[   11.460000] $24   : 0000000e 8006aa64                  
[   11.460000] $28   : 8fa9a000 8fa9bc90 00000000 8fab25b0
[   11.460000] Hi    : 00000009
[   11.460000] Lo    : 0000000a
[   11.460000] epc   : 801a15c4 ioread8+0x1c/0x24
[   11.460000]     Not tainted
[   11.460000] ra    : 8fab25b0 ata_sff_check_status+0x10/0x20 [libata]
[   11.460000] Status: 1000f402 KERNEL EXL 
[   11.460000] Cause : 9080001c
[   11.460000] PrId  : 00019374 (MIPS 24Kc)
[   11.460000] Modules linked in: sata_sil libata sd_mod scsi_mod gpio_button_hotplug ext4 jbd2 mbcache usbcore nls_base usb_common crc16 crypto_hash
[   11.460000] Process scsi_eh_0 (pid: 332, threadinfo=8fa9a000, task=8f97ce88, tls=00000000)
[   11.460000] Stack : 00000000 8fa094c0 00000000 8faa66f8 8fa08000 8f9f60d8 8fa096d0 8fab5ac0
          8fa094c0 8fa096f0 00000000 00000001 00000000 8faadc24 00000000 8fa094c0
          8fa094c0 00000000 8fa094c0 8faaf8a8 00000001 8fa09a30 00000020 8faad5bc
          00000001 00000000 00000000 00000000 00000000 ffff930f 00000001 8fab3598
          00000004 00000000 00000000 00000000 8fa094c0 00000001 00030000 8fa08000
          ...
[   11.460000] Call Trace:
[   11.460000] [<801a15c4>] ioread8+0x1c/0x24
[   11.460000] [<8f9f60d8>] 0x8f9f60d8
[   11.460000] 
[   11.460000] 
Code: 90420000  8fbf0014  27bd0018 <03e00008> 304200ff  27bdffe8  afb00010  309000ff  afbf0014 
[   11.630000] ---[ end trace 097cb9e8926a8c84 ]---
[   81.960000] random: nonblocking pool is initialized
[  127.100000] init: - preinit -
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
[  130.070000] ar71xx: pll_reg 0xb8050014: 0x110000
[  130.070000] eth0: link up (1000Mbps/Full duplex)
[  131.280000] mount_root: mounting /dev/root
[  131.290000] mount_root: loading kmods from internal overlay
[  131.450000] usbcore: registered new interface driver usb-storage
[  131.670000] __nand_correct_data: uncorrectable ECC error
[  131.680000] blk_update_request: I/O error, dev mtdblock4, sector 0
[  131.690000] blk_update_request: I/O error, dev mtdblock4, sector 8
[  131.690000] blk_update_request: I/O error, dev mtdblock4, sector 16
[  131.700000] __nand_correct_data: uncorrectable ECC error
[  131.710000] blk_update_request: I/O error, dev mtdblock4, sector 24
[  131.720000] __nand_correct_data: uncorrectable ECC error
[  131.720000] blk_update_request: I/O error, dev mtdblock4, sector 0
[  131.720000] Buffer I/O error on dev mtdblock4, logical block 0, async page read
[  132.150000] block: attempting to load /etc/config/fstab
[  132.200000] block: extroot: not configured
[  132.230000] eth0: link down
[  132.240000] procd: - early -
[  132.250000] procd: - watchdog -
[  132.820000] procd: - ubus -
[  133.830000] procd: - init -
Please press Enter to activate this console.
[  135.030000] NET: Registered protocol family 10
[  135.040000] ip6_tables: (C) 2000-2006 Netfilter Core Team
[  135.110000] Loading modules backported from Linux version master-2015-03-09-0-g141f155
[  135.110000] Backport generated by backports.git backports-20150129-0-gdd4a670
[  135.120000] ip_tables: (C) 2000-2006 Netfilter Core Team
[  135.140000] nf_conntrack version 0.5.0 (4000 buckets, 16000 max)
[  135.170000] xt_time: kernel timezone is -0000
[  135.230000] cfg80211: Calling CRDA to update world regulatory domain
[  135.230000] cfg80211: World regulatory domain updated:
[  135.240000] cfg80211:  DFS Master region: unset
[  135.240000] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[  135.250000] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[  135.260000] cfg80211:   (2457000 KHz - 2482000 KHz @ 20000 KHz, 92000 KHz AUTO), (N/A, 2000 mBm), (N/A)
[  135.270000] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm), (N/A)
[  135.280000] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (N/A)
[  135.290000] cfg80211:   (5250000 KHz - 5330000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (0 s)
[  135.300000] cfg80211:   (5490000 KHz - 5730000 KHz @ 160000 KHz), (N/A, 2000 mBm), (0 s)
[  135.310000] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[  135.310000] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm), (N/A)
[  135.820000] PPP generic driver version 2.4.2
[  135.830000] NET: Registered protocol family 24
[  140.000000] __nand_correct_data: uncorrectable ECC error
[  140.010000] blk_update_request: I/O error, dev mtdblock4, sector 0
[  140.020000] blk_update_request: I/O error, dev mtdblock4, sector 8
[  140.020000] blk_update_request: I/O error, dev mtdblock4, sector 16
[  140.030000] __nand_correct_data: uncorrectable ECC error
[  140.040000] blk_update_request: I/O error, dev mtdblock4, sector 24
[  140.060000] __nand_correct_data: uncorrectable ECC error
[  140.060000] blk_update_request: I/O error, dev mtdblock4, sector 0
[  140.060000] Buffer I/O error on dev mtdblock4, logical block 0, async page read
[  143.010000] device eth0 entered promiscuous mode
[  143.010000] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[  143.050000] device eth1 entered promiscuous mode
[  143.050000] br-lan: port 2(eth1) entered forwarding state
[  143.060000] br-lan: port 2(eth1) entered forwarding state
[  143.060000] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready
[  143.990000] br-lan: port 2(eth1) entered disabled state
[  145.090000] ar71xx: pll_reg 0xb8050014: 0x110000
[  145.090000] eth0: link up (1000Mbps/Full duplex)
[  145.110000] ar71xx: pll_reg 0xb8050010: 0x110000
[  145.110000] eth1: link up (1000Mbps/Full duplex)
[  145.120000] br-lan: port 1(eth0) entered forwarding state
[  145.120000] br-lan: port 1(eth0) entered forwarding state
[  145.130000] br-lan: port 2(eth1) entered forwarding state
[  145.130000] br-lan: port 2(eth1) entered forwarding state
[  147.110000] Atheros AR8216/AR8236/AR8316 ag71xx-mdio.0:00: Port 1 is up
[  147.120000] br-lan: port 1(eth0) entered forwarding state
[  147.130000] br-lan: port 2(eth1) entered forwarding state



BusyBox v1.23.2 (2016-01-02 20:28:42 CET) built-in shell (ash)

  _______                     ________        __
 |       |.-----.-----.-----.|  |  |  |.----.|  |_
 |   -   ||  _  |  -__|     ||  |  |  ||   _||   _|
 |_______||   __|_____|__|__||________||__|  |____|
          |__| W I R E L E S S   F R E E D O M
 -----------------------------------------------------
 CHAOS CALMER (15.05.1, r48532)
 -----------------------------------------------------
  * 1 1/2 oz Gin            Shake with a glassful
  * 1/4 oz Triple Sec       of broken ice and pour
  * 3/4 oz Lime Juice       unstrained into a goblet.
  * 1 1/2 oz Orange Juice
  * 1 tsp. Grenadine Syrup
 -----------------------------------------------------
root@OpenWrt:/#

Anyone having an idea what's wrong with the hardware/kernel module?

Thanx for any hint!