diff options
| -rw-r--r-- | Documentation/firmware_class/README | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/Documentation/firmware_class/README b/Documentation/firmware_class/README index 7eceaff63f5..815b711bcd8 100644 --- a/Documentation/firmware_class/README +++ b/Documentation/firmware_class/README @@ -18,32 +18,40 @@ High level behavior (mixed): ============================ - kernel(driver): calls request_firmware(&fw_entry, $FIRMWARE, device) - - userspace: + 1), kernel(driver): + - calls request_firmware(&fw_entry, $FIRMWARE, device) + - kernel searchs the fimware image with name $FIRMWARE directly + in the below search path of root filesystem: + "/lib/firmware/updates/" UTS_RELEASE, + "/lib/firmware/updates", + "/lib/firmware/" UTS_RELEASE, + "/lib/firmware" + - If found, goto 7), else goto 2) + + 2), userspace: - /sys/class/firmware/xxx/{loading,data} appear. - hotplug gets called with a firmware identifier in $FIRMWARE and the usual hotplug environment. - hotplug: echo 1 > /sys/class/firmware/xxx/loading - kernel: Discard any previous partial load. + 3), kernel: Discard any previous partial load. - userspace: + 4), userspace: - hotplug: cat appropriate_firmware_image > \ /sys/class/firmware/xxx/data - kernel: grows a buffer in PAGE_SIZE increments to hold the image as it + 5), kernel: grows a buffer in PAGE_SIZE increments to hold the image as it comes in. - userspace: + 6), userspace: - hotplug: echo 0 > /sys/class/firmware/xxx/loading - kernel: request_firmware() returns and the driver has the firmware + 7), kernel: request_firmware() returns and the driver has the firmware image in fw_entry->{data,size}. If something went wrong request_firmware() returns non-zero and fw_entry is set to NULL. - kernel(driver): Driver code calls release_firmware(fw_entry) releasing + 8), kernel(driver): Driver code calls release_firmware(fw_entry) releasing the firmware image and any related resource. High level behavior (driver code): |