On Sunday 05 February 2012 14:17:05 Hans Verkuil wrote:
These patches improve the tea575x-tuner module to make it up to date with the latest V4L2 frameworks.
The maxiradio driver has also been converted to use the tea575x-tuner and I've used that card to test it.
Unfortunately, this card can't read the data pin, so the new hardware seek functionality has been tested only partially (yes, it seeks, but when it finds a channel I can't read back the frequency).
Ondrej, are you able to test these patches for the sound cards that use this tea575x tuner?
Note that these two patches rely on other work that I did and that hasn't been merged yet. So it is best to pull from my git tree:
http://git.linuxtv.org/hverkuil/media_tree.git/shortlog/refs/heads/radio-pc i2
You can use the v4l-utils repository (http://git.linuxtv.org/v4l-utils.git) to test the drivers: the v4l2-compliance test should succeed and with v4l2-ctl you can test the hardware seek:
To seek down:
v4l2-ctl -d /dev/radio0 --freq-seek=dir=0
To seek up:
v4l2-ctl -d /dev/radio0 --freq-seek=dir=1
To do the compliance test:
v4l2-compliance -r /dev/radio0
It seems to work (tested with SF64-PCR - snd_fm801) but the seek is severely broken. Reading the frequency immediately after seek does not work, it always returns the old value (haven't found a delay that works). Reading it later (copied back snd_tea575x_get_freq function) works. The chip seeks randomly up or down, ignoring UP/DOWN flag and often stops at wrong place (only noise) or even outside the FM range.
So I strongly suggest not to enable this (mis-)feature. The HW seems to be completely broken (unless there's some weird bug in the code).