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authorLuis R. Rodriguez <mcgrof@kernel.org>2018-03-21 15:34:29 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-22 18:33:26 +0100
commit5d42c96e1cf98bdfea18e7d32e5f6cf75aac93b9 (patch)
tree2fc500c8568cb975a02ff63271590b472109b773 /Documentation/driver-api
parentc6263a48459934c9d07153e6d7f0fa43462d8dd2 (diff)
firmware: add firmware_request_cache() to help with cache on reboot
Some devices have an optimization in place to enable the firmware to be retaineed during a system reboot, so after reboot the device can skip requesting and loading the firmware. This can save up to 1s in load time. The mt7601u 802.11 device happens to be such a device. When these devices retain the firmware on a reboot and then suspend they can miss looking for the firmware on resume. To help with this we need a way to cache the firmware when such an optimization has taken place. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/firmware/request_firmware.rst14
1 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/driver-api/firmware/request_firmware.rst b/Documentation/driver-api/firmware/request_firmware.rst
index cc0aea880824..cf4516dfbf96 100644
--- a/Documentation/driver-api/firmware/request_firmware.rst
+++ b/Documentation/driver-api/firmware/request_firmware.rst
@@ -44,6 +44,20 @@ request_firmware_nowait
.. kernel-doc:: drivers/base/firmware_class.c
:functions: request_firmware_nowait
+Special optimizations on reboot
+===============================
+
+Some devices have an optimization in place to enable the firmware to be
+retained during system reboot. When such optimizations are used the driver
+author must ensure the firmware is still available on resume from suspend,
+this can be done with firmware_request_cache() insted of requesting for the
+firmare to be loaded.
+
+firmware_request_cache()
+-----------------------
+.. kernel-doc:: drivers/base/firmware_class.c
+ :functions: firmware_request_cache
+
request firmware API expected driver use
========================================