Currently in the rtdm gpio drivers if the pin numbers we are trying to
register in rtdm space are above 1024 we will fail to register the
pins and the driver fails to load. This happens because we use
RTDM_MAX_MINOR to limit the number of devices that can be registered.
For the gpio case adding a pin with a high pin number doesn't mean
that we have that many devices registered. For example on the
raspberry pi2 the gpio pins start at 1994, but only the gpio rtdm
driver is loaded and we don't have 1994 rtdm devices registered.
I've tested out increasing the RTDM_MAX_MAJOR to 4096, which works
but I'm not sure this is the best solution. Another solution could be
to subtract RTDM_MAX_MAJOR from the pin number if it's above
RTDM_MAX_MAJOR but we would now have pin numbers different from that
of the Linux gpio subsystem.
Any thoughts on the best approach?
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