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Description
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after updating my new Ultra-45 to be more like my old workstation, the audio driver
start failing with:
un 8 10:29:53 kuanuku audiosup: [ID 384451 kern.warning] WARNING: audio15750:
failure to power up the AC97 Codec
Jun 8 10:29:53 kuanuku audiosup: [ID 472426 kern.warning] WARNING: audio15750:
attach() failure to init chip
After some headscratching a number of powercycles, OPB upgrade, I finally netbooted
to find it working again; then I figured it must be the hires_tick = 1 setting
in /etc/system which can sometimes cause drivers to shorten their sleeps.
Reverting that setting alone made the driver work again.
A common error is to specify a delay of shorter than 10ms; and that is the
case in the audio1575 driver to:.
#define M1575_LOOP_CTR (100)
ticks = drv_usectohz(M1575_LOOP_CTR);
Both with HZ=100 and HZ=1000, this returns "1" but that makes the delay calls
being either 10ms or 1ms; the code suggests 100us is sufficient but that seems to
be wrong by a factor 100.
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