Blame view

kernel/linux-imx6_3.14.28/Documentation/ABI/testing/sysfs-class-pktcdvd 2.73 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
  What:           /sys/class/pktcdvd/
  Date:           Oct. 2006
  KernelVersion:  2.6.20
  Contact:        Thomas Maier <balagi@justmail.de>
  Description:
  
  sysfs interface
  ---------------
  
  The pktcdvd module (packet writing driver) creates
  these files in the sysfs:
  (<devid> is in format  major:minor )
  
  /sys/class/pktcdvd/
      add            (0200)  Write a block device id (major:minor)
                             to create a new pktcdvd device and map
                             it to the block device.
  
      remove         (0200)  Write the pktcdvd device id (major:minor)
                             to it to remove the pktcdvd device.
  
      device_map     (0444)  Shows the device mapping in format:
                               pktcdvd[0-7] <pktdevid> <blkdevid>
  
  /sys/class/pktcdvd/pktcdvd[0-7]/
      dev                   (0444) Device id
      uevent                (0200) To send an uevent.
  
  /sys/class/pktcdvd/pktcdvd[0-7]/stat/
      packets_started       (0444) Number of started packets.
      packets_finished      (0444) Number of finished packets.
  
      kb_written            (0444) kBytes written.
      kb_read               (0444) kBytes read.
      kb_read_gather        (0444) kBytes read to fill write packets.
  
      reset                 (0200) Write any value to it to reset
                                   pktcdvd device statistic values, like
                                   bytes read/written.
  
  /sys/class/pktcdvd/pktcdvd[0-7]/write_queue/
      size                  (0444) Contains the size of the bio write
                                   queue.
  
      congestion_off        (0644) If bio write queue size is below
                                   this mark, accept new bio requests
                                   from the block layer.
  
      congestion_on         (0644) If bio write queue size is higher
                                   as this mark, do no longer accept
                                   bio write requests from the block
                                   layer and wait till the pktcdvd
                                   device has processed enough bio's
                                   so that bio write queue size is
                                   below congestion off mark.
                                   A value of <= 0 disables congestion
                                   control.
  
  
  Example:
  --------
  To use the pktcdvd sysfs interface directly, you can do:
  
  # create a new pktcdvd device mapped to /dev/hdc
  echo "22:0" >/sys/class/pktcdvd/add
  cat /sys/class/pktcdvd/device_map
  # assuming device pktcdvd0 was created, look at stat's
  cat /sys/class/pktcdvd/pktcdvd0/stat/kb_written
  # print the device id of the mapped block device
  fgrep pktcdvd0 /sys/class/pktcdvd/device_map
  # remove device, using pktcdvd0 device id   253:0
  echo "253:0" >/sys/class/pktcdvd/remove