Re: KWorld ATSC 115 all static

[David Engel <david@istwok.net>]

On Wed, Feb 11, 2009 at 05:43:29AM -0200, Mauro Carvalho Chehab wrote:
> On Tue, 10 Feb 2009 21:50:16 -0600
> David Engel <david@istwok.net> wrote:
> > MythTV eventually worked too, but I had to do the
> > "unload/reload modules and run tvtime" procedure I reported earlier
> > when I tried Hans' kworld tree.
> 
> Maybe this is a race condition I have here with tda1004x. With tda1004x, the i2c
> bus shouldn't be used by any other device during the firmware transfers,
> otherwise the firmware load will fail, and tda1004x goes into an unstable
> state. With this device, it even affects all subsequent i2c acesses. The only
> alternative to recover tda1004x is to reboot the card (e. g. with my cardbus
> device, I have to physically remove it and re-insert).
> 
> What happens is that some softwares (including udev) open the device, and send
> some VIDIOC_G_TUNER in order to check some tuner characteristics. However, this
> command generates some i2c transfers, to retrieve signal strength. If this
> happens while the firmware is being loaded, the bug occurs.
> 
> In order to fix, a careful review of all locks on the driver is needed. We will
> likely need to change the demod interface for the boards that have this
> trouble, in order to be aware of when a firmware transfer started.
> 
> This lock review is currently on my TODO list.
> 
> To be sure that this is the case, could you please add this on
> your /etc/modprobe (or at a file inside /etc/modprobe.d):
> 
> 	options nxt200x debug=1
> 	options tuner-simple debug=1
> 	options tuner debug=1
> 	options dvb-core frontend_debug=1
> 
> And test again, sending us the produced logs when the device works and when it
> breaks. I guess we'll discover some tuner dmesg's in the middle of the firmware
> load sequence.

I will do this, but it will be tomorrow evening before I can get to
it.

David
-- 
David Engel
david@istwok.net