drivers: iio: dummy: Unable to add channels to simple_dummy_channel

valdis.kletnieks at valdis.kletnieks at
Wed Jan 23 13:57:33 EST 2019

On Wed, 23 Jan 2019 23:25:59 +0530, Bharath Vedartham said:
> I am trying to add the 3-axis compass data channels to the
> simple_dummy_channel. I have mounted configfs and am able to load the
> modules correctly. Is this the right approach? printk is not printing
> anything to syslogs.

Do you have some printk's in your probing/open routines that show that you
in fact properly found and acquired the compass hardware? Remember that
the mere fact that a module will modprobe does not mean it's correct. Bonus
points if you have the stuff in place for udev or whatever to autoload your
driver, that's an additional indication you're on the right track.

If I wanted to, I could built the driver for a 622mbit/sec ATM connection, even
though I haven't seen one of those in a *long* time. They were only ever in
wide use in long-haul networking, as it was at the time the sort of thing that
major providers used for their core backbones, sold as an OC12, and evaporated
when gigabit interfaces became cheap enough for large corporations). I've seen
ATM cards for desktop PCs, but never for a laptop.

But if I built it, it would modprobe.

For the curious: (Prices were for the days when these things were still common)

T-1 - 1.544 megabits per second (24 DS0 lines) Ave. cost $250.-$500./mo.
T-3 - 43.232 megabits per second (28 T-1s) Ave. cost $4,000.-$16,000./mo.
OC-3 - 155 megabits per second (100 T-1s) Ave. cost $20,000.-$45,000./mo.
OC-12 - 622 megabits per second (4 OC3s) no estimated price available
OC-48 - 2.5 gigabits per seconds (4 OC12s) no estimated price available
OC-192 - 9.6 gigabits per second (4 OC48s)

(A DS0 was 64 kilobits per second, and the digitized form of 1 regular phone line. It's
no accident that in modem days, 56K was the highest download speed)

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