Messages in this thread | | | Date | Tue, 17 Dec 2013 23:09:06 +0200 | From | Antti Palosaari <> | Subject | Re: stable regression: tda18271_read_regs: [1-0060|M] ERROR: i2c_transfer returned: -19 |
| |
Off-topic, Cc:s dropped, related to DVB / V4L2 tuner communication problems.
On 17.12.2013 07:39, Devin Heitmueller wrote: > Hi Connor, > > On Tue, Dec 17, 2013 at 12:28 AM, Connor Behan <connor.behan@gmail.com> wrote: >> Thanks for the detailed answer. I have tried your patch and updated the >> wiki page. Would a 950 or 950Q be safer to buy next time? > > The 950 has long since been obsoleted. You cannot buy them anymore. > The 950q though is well supported and doesn't have this issue as it > uses a different chip. > >> On 14/12/13 05:17 PM, Devin Heitmueller wrote: >>> I had a patch kicking around which fixed part of the issue, but it >>> didn't completely work because of the lgdt3305 having AGC enabled at >>> chip powerup (which interferes with analog tuning on the shared >>> tuner), and the internal v4l-dvb APIs don't provide any easy way to >>> reset the AGC from the analog side of the device. >> >> By this do you mean that the functions exist but they aren't part of the >> public API? Maybe this problem can be addressed if there is ever "v4l3" >> or some other reason to break compatibility. > > No, these are internal APIs that dictate how the various driver > components talk to each other. Because the V4L and DVB subsystems > were developed independently of each other, they do a really crappy > job of communicating between them (a problem which manifests itself in > particular when sharing hardware resources such as tuners). > > The problem *can* be fixed, but it would likely require > extensions/changes to the basic frameworks used to communicate between > the different drivers.
That shared DVB / V4L2 tuner is one problem that I have also currently (SDR is on V4L2 API and DTV is provided via DVB API). I have decided to try model where I separate RF tuner totally independent used DVB / V4L2 APIs, just to plain I2C driver model. Idea is here to provide needed set of general callbacks and communication and device binding is done via I2C driver model. I am not sure though if there is any big caveats I haven't realized yet...
regards Antti
-- http://palosaari.fi/
| |