[linux-dvb] [PATCH] XC5000 tuner improvement/clean up

John Massengale johnrobertmassengale at gmail.com
Wed Jan 30 19:10:41 CET 2008

On Jan 27, 2008 7:58 AM, Timothy E. Krantz <tkrantz at stahurabrenner.com>

> > Hi, all,
> >
> > This patch improves the performance of the xc5000 tuner driver.
> >
> > 1. Now, only one xc5000_priv struct is used for each physical tuner
> >    instead of one for each attach (analog/digital). This
> > avoids potential
> >    inconsistence such as the status of the firmware loading changed by
> >    one instance of the driver and the other instance not
> > being aware of it.
> >    It is based on the tuner-xc2028.c code.
> >
> > 2. Removed a layer of function call for xc_reset().
> >
> > 3. Replaced all calls to xc_wait() by a direct msleep() call
> > (which is all
> >    xc_wait does).
> >
> > 4. Changed the xc_wait(100) in xc_write_reg() to msleep(5).
> > The comment
> >    says wait 5 ms, was the 100 a typo? In any case, this improved the
> >    tuner performace greatly (much faster lock).
> >
> > 5. Added a module parameter "allow_shutdown", which is defaulted to 0.
> >    If enabled, the xc5000_sleep() function will indeed shutdown the
> >    tuner device. On the 800i, this is fine with analog, but digital
> >    still cannot get a lock after shutdown and reinitialized, with no
> >    apparent error message. Please test this on other cards.
> >
> > 6. Some minor clean up.
> >
> > The patch is tested on the Pinnacle 800i. Before the patch,
> > tvtime and azap works with analog/digital tv, but with very
> > slow tuning and locking. Mythtv had problems with analog tv
> > frequently (with the "errors are encountered during video
> > play back" message). Most likely, that was due to the slow
> > tuning of the xc5000.
> >
> > After the patch, both analog and digital tv saw great improvements.
> > Mythtv can consistently lock in both analog and digital
> > channels. I haven't run into the video play back errors yet
> > so far after torturing mythtv with channel changing and
> > switching between different input source/multiple cards
> > several dozen times.
> >
> > I still could not get audio (analog) in mythtv, but I suspect
> > that is a problem with my mythtv setup rather than the driver.
> >
> > Comments are welcome and please test and post your experience. Thanks!
> Sir,
> Prior to your patch when using my 800i each time I tried to go from  an
> analog to a digital station or vice versa using mythtv I got the "errors
> encountered during video playback" issue.
> With this patch installed going from analog to digital works fine for me
> but
> switching from digital to analog still results in the same error.
> Channel lock is MUCH faster.
> Thanks for your efforts!
> Tim
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I was having an issue getting the Pinnacle 800i to pick up analog cable
channels so I patched the source with this patch and compiled/installed this
version of the driver and I am still having this problem (The ATSC/QAM
tuning works perfectly, the remote is working too). I have not tried through
XAWTV yet, but through MythTV I can see it tune the channel clearly for
about a second, then it fades into colored static. I know the source is OK,
because I have an Hauppauge Wintv-USB2 hooked up that tunes the analog cable
channels with no problem. I had the analog working before so I am not sure
what happened now. Wrong module loaded or something? When scanning for
channels it is definitely a LOT faster. I also have a Kworld 110 ATSC card
installed as well, I wonder if it is conflicting somehow? Anybody have any

Even if the analog tuning starts working again, there was some discussion
about what would happen if MythTV or some other app tried to use both
sources to record two different shows? Is that really an issue?


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