>>> I need some assistance in troubleshooting problem with passing a modprobe parameter to the lirc_zilog module.
>>>
>>> I'm running Fedora 19 with the most recent updates:
>>>
>>> # uname -r
>>> 3.12.11-201.fc19.x86_64
>>>
>>> I have a file /etc/modprobe.d/lirc_zilog.conf file that contains the following:
>>>
>>> # cat /etc/modprobe.d/lirc_zilog.conf
>>> options lirc_zilog tx_only=1
>>>
>>> This file previously worked to disable the IR receive mode on the lirc_zilog module but something seems to have changed to prevent this from happening.
>>>
>>> The above parameter is being ignored since the lirc_zilog module is running both transmit and receive.
>>>
>>> Here is the command to receive IR signals:
>>>
>>> #irw
>>> 00000000000017b5 00 play Hauppauge
>>> 00000000000017b5 01 play Hauppauge
>>> 00000000000017b5 02 play Hauppauge
>>>
>>> The lirc_zilog module is being loaded at system boot time:
>>>
>>> # lsmod | grep lirc
>>> lirc_zilog 22473 0
>>> i2c_core 38476 8 drm,i915,i2c_i801,hdpvr,lirc_zilog,drm_kms_helper,i2c_algo_bit,videodev
>>> lirc_dev 19504 1 lirc_zilog
>>> rc_core 26896 1 lirc_dev
>>>
>>> The systemd-modules-load.service appears to have completed normally:
>>>
>>> # systemctl status systemd-modules-load.service
>>> systemd-modules-load.service - Load Kernel Modules
>>> Loaded: loaded (/usr/lib/systemd/system/systemd-modules-load.service; static)
>>> Active: active (exited) since Mon 2014-02-24 18:06:33 EST; 1min 46s ago
>>> Docs: man:systemd-modules-load.service(8)
>>> man:modules-load.d(5)
>>> Process: 214 ExecStart=/usr/lib/systemd/systemd-modules-load (code=exited, status=0/SUCCESS)
>>>
>>> Feb 24 18:06:32 divo systemd[1]: Starting Load Kernel Modules...
>>>
>>> The tx_only option is a valid option for lirc_zilog:
>>>
>>> # modinfo lirc_zilog
>>> filename: /lib/modules/3.12.11-201.fc19.x86_64/kernel/drivers/staging/media/lirc/lirc_zilog.ko
>>> alias: lirc_pvr150
>>> license: GPL
>>> author: Gerd Knorr, Michal Kochanowicz, Christoph Bartelmus, Ulrich Mueller, Stefan Jahn, Jerome Brock, Mark Weaver, Andy Walls
>>> description: Zilog/Hauppauge infrared transmitter driver (i2c stack)
>>> depends: i2c-core,lirc_dev
>>> staging: Y
>>> intree: Y
>>> vermagic: 3.12.11-201.fc19.x86_64 SMP mod_unload
>>> signer: Fedora kernel signing key
>>> sig_key: FC:A0:01:2C:8A:A6:A3:A0:0F:CC:4E:16:E4:8C:17:FD:D9:C6:31:21
>>> sig_hashalgo: sha256
>>> parm: minor:Preferred minor device number (int)
>>> parm: debug:Enable debugging messages (bool)
>>> parm: tx_only:Only handle the IR transmit function (bool)
>>>
>>> I can manually unload the lirc_zilog module and manually reload lirc_zilog with the tx_only=1 option and lirc_zilog module works as desired with IR receive disabled.
>>>
>>> I've tried various filenames.conf and the different directories (/lib/modprobe.d) for modprobe without success.
>>>
>>> If I run dmesg and grep for IR, I see that lirc_zilog is probing for IR Rx and IR Tx.
>>>
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: probing IR Rx on Hauppage HD PVR I2C (i2c-8)
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: probe of IR Rx on Hauppage HD PVR I2C (i2c-8) done. Waiting on IR Tx.
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: probe of IR Rx on Hauppage HD PVR I2C (i2c-8) done
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: probing IR Tx on Hauppage HD PVR I2C (i2c-8)
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: IR unit on Hauppage HD PVR I2C (i2c-8) registered as lirc0 and ready
>>> [Mon Feb 24 18:06:34 2014] lirc_zilog: probe of IR Tx on Hauppage HD PVR I2C (i2c-8) done
>>>
>>> Previously when the tx_only=1 option was being properly processes, the lirc_zilog module was only probing for IR Tx.
>>>
>>> Looking at the systemd entries from dmesg doesn't give any hints for why the lirc_zilog.conf options file isn't being read.
>>>
>>> Looking at the output from journalctl -b doesn't provide any clues.
>>>
>>> I've exhausted my ability to troubleshoot the systemd-modules-load.service to see the details of what is going on during the boot process.
>>>
>>> I need help with how to enable debug on the systemd-modules-load process or help of where to look next to resolve this issue.
>>>
>>> Thanks in advance for any assistance you can provide.
>>
>>I think you're saying that if you manually unload the module and then load it the .conf file is honored and loaded as you want.
>>
>>If so, did you run dracut to create a new initramfs with the changes you made?
>>

Thanks for your help. You were correct that it was a problem with the kernel needing to be rebuilt after adding/changing files to the /etc/modules-load.d and /etc/modprobe.d directory.

Made a copy of the existing /boot/initramfs-$(uname -r).img file and re-ran the command to rebuild the kernel file:

# dracut -f /boot/initramfs-$(uname -r).img $(uname -r)

I went back and checked the man pages on modules-load.d and modprobe.d and neither mentions having to run dracut or mkinitrd after adding file to these directories. Lesson learned.