[media] lirc_zilog: Update TODO.lirc_zilog

Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Andy Walls 2011-01-16 15:21:27 -03:00 committed by Mauro Carvalho Chehab
parent c2790c7192
commit 1f1bfaa0a2

View file

@ -1,13 +1,37 @@
The binding between hdpvr and lirc_zilog is currently disabled,
1. Both ir-kbd-i2c and lirc_zilog provide support for RX events.
The 'tx_only' lirc_zilog module parameter will allow ir-kbd-i2c
and lirc_zilog to coexist in the kernel, if the user requires such a set-up.
However the IR unit will not work well without coordination between the
two modules. A shared mutex, for transceiver access locking, needs to be
supplied by bridge drivers, in struct IR_i2_init_data, to both ir-kbd-i2c
and lirc_zilog, before they will coexist usefully. This should be fixed
before moving out of staging.
2. References and locking need careful examination. For cx18 and ivtv PCI
cards, which are not easily "hot unplugged", the imperfect state of reference
counting and locking is acceptable if not correct. For USB connected units
like HD PVR, PVR USB2, HVR-1900, and HVR1950, the likelyhood of an Ooops on
unplug is probably great. Proper reference counting and locking needs to be
implemented before this module is moved out of staging.
3. The binding between hdpvr and lirc_zilog is currently disabled,
due to an OOPS reported a few years ago when both the hdpvr and cx18
drivers were loaded in his system. More details can be seen at:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg09163.html
More tests need to be done, in order to fix the reported issue.
There's a conflict between ir-kbd-i2c: Both provide support for RX events.
Such conflict needs to be fixed, before moving it out of staging.
4. In addition to providing a shared mutex for transceiver access
locking, bridge drivers, if able, should provide a chip reset() callback
to lirc_zilog via struct IR_i2c_init_data. cx18 and ivtv already have routines
to perform Z8 chip resets via GPIO manipulations. This will allow lirc_zilog
to bring the chip back to normal when it hangs, in the same places the
original lirc_pvr150 driver code does. This is not strictly needed, so it
is not required to move lirc_zilog out of staging.
The way I2C probe works, it will try to register the driver twice, one
for RX and another for TX. The logic needs to be fixed to avoid such
issue.
5. Both lirc_zilog and ir-kbd-i2c support the Zilog Z8 for IR, as programmed
and installed on Hauppauge products. When working on either module, developers
must consider at least the following bridge drivers which mention an IR Rx unit
at address 0x71 (indicative of a Z8):
ivtv cx18 hdpvr pvrusb2 bt8xx cx88 saa7134