Comment=
# 5
on bug 79820<=
/a>
from Martin Peres
(In reply to comment #2=
)
> With nouveau loaded, can you grab vbios from
> /sys/kernel/debug/dri/0/vbios.rom? Or use -s prom with nvagetbios?
I just pushed a patch to nvagetbios to suggest to use -s prom when the
signature is invalid. Let's stop wasting time suggesting this.
>=20
> It's moderately likely that the reported fan rpm is just 2x what it sh=
ould
> be -- did the fan sound louder with nouveau than with the blob? See
> http=
://cgit.freedesktop.org/~darktama/nouveau/commit/
> ?id=3De3601d0869a18acc19e58f2d1216b810632d75f0 (which will be in 3.16-=
rc1).
Yes, this is likely the problem here.
>=20
> Martin -- any idea about the weird RPMs reported for the lower values?=
It probably is a bouncing problem of the Hall effect sensor. This one may n=
ot
have a proper hysteresis cycle which leads to an unstable signal during the
transition phases. The longer the transition takes, the more un-wanted
oscillation is introduced. It is possible that the fan manufacturer added a
low-pass filter on the fan that only works down to the minimum speed (35%) =
and
fails to clean up the signal after that.
In any case, this is not our bug unless nvidia is able to cope with it (whi=
ch
is impossible to test with the coolbits since they don't allow a fan speed
lower than the minimum speed). I could edit the vbios to change the minimum
speed limit and ask you to re-upload it and check if nvidia yields the same
result. Would you be interested in doing that?
(In reply to comment #3)
> The noise didn=E2=80=99t really noticeably incre=
ase. And I just checked the values
> reported by nvidia-settings. When idle, these always seem to jump in
> increments of 30 RPM (usually between 1050 and 1080). With nouveau, the
> output value jumps in increments of 60 RPM, so you are probably right =
and
> the difference is only nominal.
Perfect! Thank you :)
>=20
> In any case, I=E2=80=99m attaching the BIOS file obtained from nvagetb=
ios -s prom.
> No warnings were reported this time.
Thanks, but I don't think it will be necessary...