At Wed, 21 Jun 2006 12:58:27 +0100, James Courtier-Dutton wrote: > > >> The trouble is, that if one changes some controls on the device, e.g. > >> switching from SPDIF to ADAT digital outputs, a whole new different > >> firmware image is loaded. So, one has multiple different firmware > >> images, with one swapping between them. Should these firmware images be > >> left in the kernel then, instead of using the userspace firmware api? > >> > > > > There are some drivers in the kernel which load different firmware images > > in different modes. E.g., the ipw2200 driver can load ipw2200-bss.fw, > > ipw2200-ibss.fw or ipw2200-sniffer.fw depending on the mode set by > > iwconfig (and can switch between them at runtime). > > > > There is also an option to use a single firmware file consisting of > > multiple parts used for different modes, but this obviously has a higher > > memory overhead. IMHO this should be used only when there are some > > latency restrictions for switching modes (so that a driver can request all > > firmware parts during initialization and then load different parts without > > waiting for userspace helpers). > > > > Are all those threee fw images loaded into the driver cache memory from > userspace at modprobe time, or is each one loaded from userspace each > time a iwconfig mode changes? > I don't yet know how many different images I will have to play with. I > have so far counted the presence of 2. > Is leaving them cached in driver kernel memory considered bad practice, > and wasteful of memory space? This depends on the size and on how often you need to use them. Reading fw images invokes many processes, so it itself is no light job. Moreover, for the proper suspend/resume, you need anyway the firmware image. It'll be a bit tricky without cached fw images on memory. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
