How to find the driver (module) associated with SATA device on Linux?
For one of my applications, I have to understand the the SATA device driver flow. As per my understanding, SATA device driver should be there in the Linux kernel tree. I have referred how to find the driver module associated with a device on Linux to find the device driver for the SATA device.
$ readlink /sys/block/sda/device/driver ../../../../../../../bus/scsi/d usr@usr:/sys/bus/scsi/drivers/sd$ ll total 0 drwxr-xr-x 2 root root 0 Dec 9 17:00 ./ drwxr-xr-x 4 root root 0 Dec 9 17:00 ../ lrwxrwxrwx 1 root root 0 Dec 9 17:47 2:0:1:0 -> ../../../../devices/pci0000:00/0000:00:1f.2/ata3/host2/target2:0:1/2:0:1:0/ --w------- 1 root root 4096 Dec 9 17:47 bind --w------- 1 root root 4096 Dec 9 17:47 uevent --w------- 1 root root 4096 Dec 9 17:47 unbind usr@usr:/sys/bus/scsi/drivers/sd$ Please suggest how can I see the device driver which was actually load for SATA hard drive on my system.
I am using «Linux version 3.13.0-32-generic (buildd@phianna) (gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #57~precise1-Ubuntu SMP Tue Jul 15 03:51:20 UTC 2014» ubuntu 12.04 . Can you please elaborate what information I need to check in lsmod?
Hemant, if you are using a stock Ubuntu kernel, and it sounds like you are, much of the functionality is in modules, to make the stock kernel as flexible as possible. So, take a look at the listed module names to see which one is implementing SATA. I seem to remember it is sg (tldp.org/HOWTO/SCSI-2.4-HOWTO/sg.html), but just do a search for «moulestring linux kernel module» for possible likely strings.
Hey,Thanks for the help, my final goal is to understand the software flow between the SATA Host(HBA) and a SATA device driver(SATA Hard Disk).To understand the flow I need to go through the SATA Host and Device driver code .I know AHCI can be used as a HBA in linux kernel which is at «linux-xlnx-xilinx_v2.6.30/drivers/ata/» but I am not sure about the SATA device driver.Can you point out which device driver code should I look in kernel tree to understand the device code flow or Can you point me somewhere I can get the sample SATA device driver code to undestand Host and Device communication?
2 Answers 2
Use udevadm info as described in the other answer to the link you mentioned. Here’s an example with a different grep-variant to reduce the output, while walking the /sys tree backwards:
$ udevadm info -a -n /dev/sda | egrep 'looking|DRIVER' looking at device '/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda': DRIVER=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0': DRIVERS=="sd" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0': DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1/host0': DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2/ata1': DRIVERS=="" looking at parent device '/devices/pci0000:00/0000:00:1f.2': DRIVERS=="ahci" looking at parent device '/devices/pci0000:00': DRIVERS=="" So you can see that on my system, /dev/sda maps to SCSI device 0:0:0:0 , which is attached to ata1 on PCI device 0:00:1f.2 (which is the host adapter)
The driver sd is responsible for handling the block device, while the driver ahci is responsible for handling the SATA host adapter.
How do I make Linux recognize a new SATA /dev/sda drive I hot swapped in without rebooting?
Hot swapping out a failed SATA /dev/sda drive worked fine, but when I went to swap in a new drive, it wasn’t recognized:
[root@fs-2 ~]# tail -18 /var/log/messages May 5 16:54:35 fs-2 kernel: ata1: exception Emask 0x10 SAct 0x0 SErr 0x50000 action 0xe frozen May 5 16:54:35 fs-2 kernel: ata1: SError: < PHYRdyChg CommWake >May 5 16:54:40 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:45 fs-2 kernel: ata1: device not ready (errno=-16), forcing hardreset May 5 16:54:45 fs-2 kernel: ata1: soft resetting link May 5 16:54:50 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:54:55 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:54:55 fs-2 kernel: ata1: soft resetting link May 5 16:55:00 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:05 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:05 fs-2 kernel: ata1: soft resetting link May 5 16:55:10 fs-2 kernel: ata1: link is slow to respond, please be patient (ready=0) May 5 16:55:40 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:40 fs-2 kernel: ata1: limiting SATA link speed to 1.5 Gbps May 5 16:55:40 fs-2 kernel: ata1: soft resetting link May 5 16:55:45 fs-2 kernel: ata1: SRST failed (errno=-16) May 5 16:55:45 fs-2 kernel: ata1: reset failed, giving up May 5 16:55:45 fs-2 kernel: ata1: EH complete I tried a couple things to make the server find the new /dev/sda, such as rescan-scsi-bus.sh but they didn’t work:
[root@fs-2 ~]# echo "---" > /sys/class/scsi_host/host0/scan -bash: echo: write error: Invalid argument [root@fs-2 ~]# [root@fs-2 ~]# /root/rescan-scsi-bus.sh -l [snip] 0 new device(s) found. 0 device(s) removed. [root@fs-2 ~]# [root@fs-2 ~]# ls /dev/sda ls: /dev/sda: No such file or directory I ended up rebooting the server. /dev/sda was recognized, I fixed the software RAID, and everything is fine now. But for next time, how can I make Linux recognize a new SATA drive I have hot swapped in without rebooting? The operating system in question is RHEL5.3:
[root@fs-2 ~]# cat /etc/redhat-release Red Hat Enterprise Linux Server release 5.3 (Tikanga) The hard drive is a Seagate Barracuda ES.2 SATA 3.0-Gb/s 500-GB, model ST3500320NS. Here is the lscpi output:
[root@fs-2 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0a.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0d.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0e.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) Update: In perhaps a dozen cases, we’ve been forced to reboot servers because hot swap hasn’t «just worked.» Thanks for the answers to look more into the SATA controller. I’ve included the lspci output for the problematic system above (hostname: fs-2). I could still use some help understanding what exactly isn’t supported hardware-wise in terms of hot swap for that system. Please let me know what other output besides lspci might be useful. The good news is that hot swap «just worked» today on one of our servers (hostname: www-1), which is very rare for us. Here is the lspci output:
[root@www-1 ~]# lspci 00:00.0 RAM memory: nVidia Corporation MCP55 Memory Controller (rev a2) 00:01.0 ISA bridge: nVidia Corporation MCP55 LPC Bridge (rev a3) 00:01.1 SMBus: nVidia Corporation MCP55 SMBus (rev a3) 00:02.0 USB Controller: nVidia Corporation MCP55 USB Controller (rev a1) 00:02.1 USB Controller: nVidia Corporation MCP55 USB Controller (rev a2) 00:04.0 IDE interface: nVidia Corporation MCP55 IDE (rev a1) 00:05.0 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.1 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:05.2 IDE interface: nVidia Corporation MCP55 SATA Controller (rev a3) 00:06.0 PCI bridge: nVidia Corporation MCP55 PCI bridge (rev a2) 00:08.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:09.0 Bridge: nVidia Corporation MCP55 Ethernet (rev a3) 00:0b.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0c.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:0f.0 PCI bridge: nVidia Corporation MCP55 PCI Express bridge (rev a3) 00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 00:19.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration 00:19.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map 00:19.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller 00:19.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control 00:19.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control 03:00.0 VGA compatible controller: Matrox Graphics, Inc. MGA G200e [Pilot] ServerEngines (SEP1) (rev 02) 04:00.0 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 04:00.1 PCI bridge: NEC Corporation uPD720400 PCI Express - PCI/PCI-X Bridge (rev 06) 09:00.0 SCSI storage controller: LSI Logic / Symbios Logic SAS1064ET PCI-Express Fusion-MPT SAS (rev 04)