tools/testing/selftests/firmware/fw_userhelper.sh

   1 #!/bin/sh
   2 # This validates that the kernel will fall back to using the user helper
   3 # to load firmware it can't find on disk itself. We must request a firmware
   4 # that the kernel won't find, and any installed helper (e.g. udev) also
   5 # won't find so that we can do the load ourself manually.
   6 set -e
   7
   8 modprobe test_firmware
   9
  10 DIR=/sys/devices/virtual/misc/test_firmware
  11
  12 # CONFIG_FW_LOADER_USER_HELPER has a sysfs class under /sys/class/firmware/
  13 # These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
  14 # as an indicator for CONFIG_FW_LOADER_USER_HELPER.
  15 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; else echo no; fi)
  16
  17 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
  18        OLD_TIMEOUT=$(cat /sys/class/firmware/timeout)
  19 else
  20         echo "usermode helper disabled so ignoring test"
  21         exit 0
  22 fi
  23
  24 FWPATH=$(mktemp -d)
  25 FW="$FWPATH/test-firmware.bin"
  26
  27 test_finish()
  28 {
  29         echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
  30         rm -f "$FW"
  31         rmdir "$FWPATH"
  32 }
  33
  34 load_fw()
  35 {
  36         local name="$1"
  37         local file="$2"
  38
  39         # This will block until our load (below) has finished.
  40         echo -n "$name" >"$DIR"/trigger_request &
  41
  42         # Give kernel a chance to react.
  43         local timeout=10
  44         while [ ! -e "$DIR"/"$name"/loading ]; do
  45                 sleep 0.1
  46                 timeout=$(( $timeout - 1 ))
  47                 if [ "$timeout" -eq 0 ]; then
  48                         echo "$0: firmware interface never appeared" >&2
  49                         exit 1
  50                 fi
  51         done
  52
  53         echo 1 >"$DIR"/"$name"/loading
  54         cat "$file" >"$DIR"/"$name"/data
  55         echo 0 >"$DIR"/"$name"/loading
  56
  57         # Wait for request to finish.
  58         wait
  59 }
  60
  61 trap "test_finish" EXIT
  62
  63 # This is an unlikely real-world firmware content. :)
  64 echo "ABCD0123" >"$FW"
  65 NAME=$(basename "$FW")
  66
  67 # Test failure when doing nothing (timeout works).
  68 echo 1 >/sys/class/firmware/timeout
  69 echo -n "$NAME" >"$DIR"/trigger_request
  70 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
  71         echo "$0: firmware was not expected to match" >&2
  72         exit 1
  73 else
  74         echo "$0: timeout works"
  75 fi
  76
  77 # Put timeout high enough for us to do work but not so long that failures
  78 # slow down this test too much.
  79 echo 4 >/sys/class/firmware/timeout
  80
  81 # Load this script instead of the desired firmware.
  82 load_fw "$NAME" "$0"
  83 if diff -q "$FW" /dev/test_firmware >/dev/null ; then
  84         echo "$0: firmware was not expected to match" >&2
  85         exit 1
  86 else
  87         echo "$0: firmware comparison works"
  88 fi
  89
  90 # Do a proper load, which should work correctly.
  91 load_fw "$NAME" "$FW"
  92 if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
  93         echo "$0: firmware was not loaded" >&2
  94         exit 1
  95 else
  96         echo "$0: user helper firmware loading works"
  97 fi
  98
  99 exit 0