Lines Matching refs:firmware

5 When Linux resumes from suspend some device drivers require firmware lookups to
7 firmware lookups are not possible, during this short period of time firmware
9 the root filesystem for firmware delays user experience with device
10 functionality. In order to support these requirements the firmware
11 infrastructure implements a firmware cache for device drivers for most API
14 The firmware cache makes using certain firmware API calls safe during a device
16 the firmware by themselves for dealing with firmware loss during system resume.
18 The firmware cache works by requesting for firmware prior to suspend and
19 caching it in memory. Upon resume device drivers using the firmware API will
20 have access to the firmware immediately, without having to wait for the root
24 Some implementation details about the firmware cache setup:
26 * The firmware cache is setup by adding a devres entry for each device that
29 * If an asynchronous call is used the firmware cache is only set up for a
32   userspace for the firmware request through the sysfs fallback mechanism
33   if the firmware file is not found.
35 * If the firmware cache is determined to be needed as per the above two
36   criteria the firmware cache is setup by adding a devres entry for the
37   device making the firmware request.
39 * The firmware devres entry is maintained throughout the lifetime of the
40   device. This means that even if you release_firmware() the firmware cache
44   as the firmware cache is set up during suspend, the timeout is set back to
47 * Upon suspend any pending non-uevent firmware requests are killed to avoid
49   calls requiring the non-uevent therefore need to implement their own firmware
50   cache mechanism but must not use the firmware API on suspend.