lkml.org 
[lkml]   [2012]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [advice sought] EOMA68 kernel support
    >  of particular concern is that a CPU card could be running on (small!)
    > backup battery / supercapacitor whilst being hot-swapped, and thus
    > that means that the LCD module (drivers/eoma68/lcd.ko?) would need to
    > be loaded and unloaded from userspace (udev). that's not going to be
    > a problem, is it? i may just be imagining skeletons in the closet,
    > here.

    Your device tree describes devices. Your bus creates them when you
    hotplug and it removes them when you hot unplug. The rest is the drivers
    problem to behave properly, and refcount right.

    > * it's the purposes to which the 16 GPIOs can be put that will be
    > radically different from one I/O board to the next. GPIO 0 could be
    > "powerup for WIFI" on one I/O board, but "lid open/shut switch" on
    > another.

    It's "GPIO 0 of card X" and providing you remember that, watch your
    refcounting and don't remap a new device over the address space of an old
    one during a hotplug you should be fine.

    Alan


    \
     
     \ /
      Last update: 2012-03-10 20:51    [W:0.020 / U:1.176 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site