diff options
Diffstat (limited to 'Documentation/firmware_class/README')
-rw-r--r-- | Documentation/firmware_class/README | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README index 815b711bcd85..43fada989e65 100644 --- a/Documentation/firmware_class/README +++ b/Documentation/firmware_class/README | |||
@@ -22,12 +22,17 @@ | |||
22 | - calls request_firmware(&fw_entry, $FIRMWARE, device) | 22 | - calls request_firmware(&fw_entry, $FIRMWARE, device) |
23 | - kernel searchs the fimware image with name $FIRMWARE directly | 23 | - kernel searchs the fimware image with name $FIRMWARE directly |
24 | in the below search path of root filesystem: | 24 | in the below search path of root filesystem: |
25 | User customized search path by module parameter 'path'[1] | ||
25 | "/lib/firmware/updates/" UTS_RELEASE, | 26 | "/lib/firmware/updates/" UTS_RELEASE, |
26 | "/lib/firmware/updates", | 27 | "/lib/firmware/updates", |
27 | "/lib/firmware/" UTS_RELEASE, | 28 | "/lib/firmware/" UTS_RELEASE, |
28 | "/lib/firmware" | 29 | "/lib/firmware" |
29 | - If found, goto 7), else goto 2) | 30 | - If found, goto 7), else goto 2) |
30 | 31 | ||
32 | [1], the 'path' is a string parameter which length should be less | ||
33 | than 256, user should pass 'firmware_class.path=$CUSTOMIZED_PATH' | ||
34 | if firmware_class is built in kernel(the general situation) | ||
35 | |||
31 | 2), userspace: | 36 | 2), userspace: |
32 | - /sys/class/firmware/xxx/{loading,data} appear. | 37 | - /sys/class/firmware/xxx/{loading,data} appear. |
33 | - hotplug gets called with a firmware identifier in $FIRMWARE | 38 | - hotplug gets called with a firmware identifier in $FIRMWARE |
@@ -114,3 +119,10 @@ | |||
114 | on the setup, so I think that the choice on what firmware to make | 119 | on the setup, so I think that the choice on what firmware to make |
115 | persistent should be left to userspace. | 120 | persistent should be left to userspace. |
116 | 121 | ||
122 | about firmware cache: | ||
123 | -------------------- | ||
124 | After firmware cache mechanism is introduced during system sleep, | ||
125 | request_firmware can be called safely inside device's suspend and | ||
126 | resume callback, and callers need't cache the firmware by | ||
127 | themselves any more for dealing with firmware loss during system | ||
128 | resume. | ||