staging: comedi: comedi_test: make timer rate similar to scan rate

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The asynchronous command handling for the analog input subdevice uses a
kernel timer which expires approximately `HZ` times a second.  However,
it only needs to do anything after each scan period.  Set the timer to
expire just after the next scan period.

Although the timer expiry function `waveform_ai_interrupt()` uses
precise time values to generate the fake waveforms used to generate the
data, those time values are constructed in a precise sequence, and do
not depend on the time the timer expiry function is actually called.  So
the timer expiry rate does not have to be very precise.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Ian Abbott 2015-10-27 16:59:20 +00:00 • committed by Greg Kroah-Hartman

parent f3f24dff89

commit 4e5ffbf29c

1 changed files with 9 additions and 4 deletions

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drivers/staging/comedi/drivers/comedi_test.c

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