implementing hotplug event
My driver can catch $ACTION now. I also added the code to my class driver to make it send out the same info as a PCI hotplug event. Now my userspace app needs to open the newly loaded device driver, how do I reliably find it? I know that it is at /dev/dri/cardX but what if the user is replacing /dev with /udev or /devfs? I know the major/minor I could just mknode in my program too.
==Jon Smirl
[email protected]
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Quoted 1 line · Jon Smirl
My driver can catch $ACTION now.
You mean your userspace program, right?
Quoted 2 lines
I also added the code to my class driver to make it send out the same info as a PCI hotplug event.
That's good.
Quoted 4 lines
Now my userspace app needs to open the newly loaded device driver, how do I reliably find it? I know that it is at
/dev/dri/cardXbut what if the user is replacing /dev with /udev or /devfs? I know the major/minor I could just mknode in my program too.
To be safe, you can always just read the sysfs "dev" file, and do a mknod with that information. Otherwise you could query udev as to what it has named your device, but we don't have those hooks in udev just yet... someday soon...
thanks,
greg k-h
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Quoted 9 lines · --- Greg KH
Quoted 4 lines
Now my userspace app needs to open the newly loaded device driver, how do I reliably find it? I know that it is at
/dev/dri/cardXbut what if the user is replacing /dev with /udev or /devfs? I know the major/minor I could just mknode in my program too.To be safe, you can always just read the sysfs "dev" file, and do a mknod with that information. Otherwise you could query udev as to what it has named your device, but we don't have those hooks in udev just yet... someday soon...
I just sent the major/minor to the hotplug event in the environment variables, it seemed easier than sending out the slot id and finding "dev" in sysfs. Doing mknod from the user space app seems to be the most reliable scheme.
==Jon Smirl
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Quoted 6 lines · Jon Smirl
Quoted 5 lines · --- Greg KH
Quoted 4 lines
Now my userspace app needs to open the newly loaded device driver, how do I reliably find it? I know that it is at
/dev/dri/cardXbut what if the user is replacing /dev with /udev or /devfs? I know the major/minor I could just mknode in my program too.
Quoted 8 lines
Quoted 4 lines
To be safe, you can always just read the sysfs "dev" file, and do a mknod with that information. Otherwise you could query udev as to what it has named your device, but we don't have those hooks in udev just yet... someday soon...
I just sent the major/minor to the hotplug event in the environment variables, it seemed easier than sending out the slot id and finding "dev" in sysfs. Doing mknod from the user space app seems to be the most reliable scheme.
True, as long as your userapp is running as root :)
thanks,
greg k-h
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