On 01/20/2012 11:18 PM, Gordon Hecker wrote:
This patch fixes the following error messages with a
Terratec Cinergy T Stick Dual RC DVB-T device.
af9013: i2c wr failed=-1 reg=d607 len=1
af9015: command failed:2
af9013: i2c rd failed=-1 reg=d607 len=1
af9015: command failed:1
It implements exclusive access to i2c for only one frontend at a time
through a use-counter that is increased for each af9013_i2c_gate_ctrl-enable
or i2c-read/write and decreased accordingly. The use-counter remains
incremented after af9013_i2c_gate_ctrl-enable until the corresponding
disable.
Debug output was added.
ToDo:
* Replace frontend by adapter (the dual-tuner devices do actually
provide two adapters with one frontend each)
* move af9013_i2c_gate_mutex, locked_fe, af9013_i2c_gate_ctrl_usecnt
to the usb device
Again that same issue. But after af9013 rewrote those should not be very
significant problem... If you looked, as I can guess, AF9015 code you
can see callbacks lock that are for resolving same issue. Almost all
callbacks are locked, but I left few rarely called callbacks without
lock due to performance point of view. You can guess it causes always
latency to wait other thread finish callback...
I think you may resolve that just adding one or two callback lock more,
likely for tuner init() and sleep().
I don't like that you are adding such code for the demod driver -
problem is USB-bridge, its I2C adapter and firmware. Due to that such
code should be in AF9015 driver. There has been originally two I2C
adapters in af9015 but I removed those. And there is actually only one
I2C adapter in AF9015.
See these for more info about I2C bus connections:
http://palosaari.fi/linux/v4l-dvb/controlling_tuner_af9015_dual_demod.txt
http://palosaari.fi/linux/v4l-dvb/controlling_tuner.txt
I think that piece of code is not very important and I dont like to see
it in current af9013 driver. Do needed changes for af9015 instead.
regards
Antti
--
http://palosaari.fi/
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