Messages in this thread | | | Subject | RE: suspend/resume support for driver requires an external firmware | Date | Mon, 27 Sep 2004 11:43:12 +0800 | From | "Zhu, Yi" <> |
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Marcel Holtmann wrote: > it consumes extra runtime memory, but why not build a simple > firmware cache behind the request_firmware() interface.
I think this could be another choice, but I'd rather call it as a firmware suspend hook. Because when the system is running, the cache should be purged to save memory. swsusp (or other implementations) is required to call the firmware hook before device_suspend. The firmware hook is responsible to load all the necessary firmwares into memory before suspend so that they can be read from memory in the next request_firmware(). And we also need a firmware resume hook to free the memory.
But how about drivers read firmware themselves? They don't rely on firmware_class.
> In this case it can be transparent for the driver and we won't > have an extra workaround for suspend/resume stuff for every > driver.
I don't think it is a workaround, drivers are supposed to know best how to "save their states". Firmware is one example for now.
> How many firmwares do a normal system really have to > hold in memory for suspend/resume actions?
I don't know either. ;-)
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