[sane-devel] Re: HP 7450C - Error trying to scan in powersave mode

[Erik P. Olsen]

On Mon, 2004-08-30 at 23:22, Ren=C3=A9 Rebe wrote:
> Hi,
>=20
> sorry for the delay - at least this week I'm =C3=BCber-busy again ...
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> > OK, log attached with SANE_DEBUG_AVISION=3D7. Used xsane to produce t=
he
> > problem. The scenario was as follows:
> >=20
> > 1. Reboot
> > 2. Correct scan
> > 3. Wait half an hour
> > 4. Incorrect scan, stopped half way through with this horrible noice.
> > 5. Pulled the plug.
> >=20
> > The scan was performed on a full A4-size document. If I reduce the sc=
an
> > to, say, 5 by 5 mm the problem never occurs.
> >=20
> > Please let me know if you also need to see the image.
>=20
> Ok, the wait_4_light() function timed out. Can you try if the scanner=20
> just needs yet more time to recover from the energy saving mode? Go to=20
> the wait_4_light() function in avision.c (depending on the version of=20
> the file) around line 1941. When you scroll thru the function you modif=
y=20
> the for() loop testing for the warmup to wait longer, maybe 667 seconds=
=20
> instead of current 90 ... ;-) Patch:
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> Index: avision.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- avision.c	(revision 133)
> +++ avision.c	(working copy)
> @@ -1962,7 +1962,7 @@
>     set_double (rcmd.datatypequal, dev->data_dq);
>     set_triple (rcmd.transferlen, size);
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> -  for (try =3D 0; try < 90; ++ try) {
> +  for (try =3D 0; try < 667; ++ try) {
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>       DBG (5, "wait_4_light: read bytes %d\n", size);
>       status =3D avision_cmd (&s->av_con, &rcmd, sizeof (rcmd), 0, 0,=20
> &result, &size);
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> (Never tried this with Thunderbird and my new IMAP setup - so no idea i=
f=20
> thiis inlien patch has mangled tabs ...)
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> But when some scanners really need _that much_ time to recover, I bet I=
=20
> get other users balming the frontend to hang and I should think about=20
> some way to report this less annoyingly hanging ...

OK, I'll do this additional test, but I fear wait_4_light() will wait
forever. As I see it the scanner performs correctly after reboot, then
after the lamp has cooled off and no new reboot performed then the
disaster happens. It's like a reset is missing. I'll test if this
assumption is correct, but it takes some time because the lamp should
have ample time to cool off and unfortunately I have very little time
now. I'll see if I can squeeze in the time for the test though.

--=20
Regards,
Erik P. Olsen