Category Archives: Linux

fglrx_drv < radeon_drv

Issues with the ATI fglrx driver on my IBM ThinkPad T42p:

  • DVI output does not work (no signal).
  • Unable to play 720p video because XVideo can’t allocate enough video memory: “BadAlloc (insufficient resources for operation)”. Disabling DRI frees up enough video memory to enable successful playback.
  • After waking up from suspend, 2D performance is very bad (scrolling in gnome-terminal and firefox stutters).

None of these problems occur with the open source xorg radeon driver.

AUDIOTrak OPTOPlay

I use an AUDIOTRAK OPTOPlay to output audio digitally to my DD/DTS receiver. More than 4 months ago I submitted a patch to the ALSA project. The patch fixes a bug in the usbaudio driver that prevents the use of sample rates other than the default with the OPTOPlay. The bug report has yet to even be reviewed. Compiling a custom kernel package just for this one small fix is a waste of time, so I usually end up just patching the binary.

objdump -h /lib/modules/*/kernel/sound/usb/snd-usb-audio.ko | grep " .text" | cut -d' ' -f19

objdump -d --prefix-addresses /lib/modules/*/kernel/sound/usb/snd-usb-audio.ko | grep "cmp    $0x530a92" | cut -d' ' -f1

The above commands will output one offset each. Add the two together and you have the patch offset. Unload the snd-usb-audio module. Open up snd-usb-audio.ko in a hex editor. Overwrite 12 bytes starting at the patch offset with 0x90s. Save and close. Load the module. You should now be able to use sample rates other than the default with the OPTOPlay.

Intel PRO/Wireless 2100

I’ve started writing a Linux driver for the Intel PRO/Wireless 2100 (part of Centrino). So far it only does some basic initialization, loads the microcode and firmware, and gets the MAC address.

Linux and DRM

Linus has chimed in on DRM:

I want to make it clear that DRM is perfectly ok with Linux!

Not surprising considering what he is quoted as saying when InterVideo announced their fair use-hostile DVD player for GNU/Linux:

This is another exciting day for the Linux community. The OS continues to attract industry-leading software companies like InterVideo. Their digital video and audio products will greatly enhance the Linux multimedia experience.

I haven’t Hurd about anyone getting their GNU/Linux experience enhanced by LinDVD. The product is still only available to OEMs. IBM even bragged about rolling out “legal” DVD playback for GNU/Linux.

I’ll stick to fair use-enabling DVD players such as VLC and Ogle. They’re certainly legal in Europe. Denmark has already implemented the EUCD and the Danish Ministry of Culture has stated that circumvention for playback is legal. They have even commented on my acquittal, stating that they believe I would have been acquitted in Denmark under their implementation of the EUCD.

Centrino and Linux

I fired off the following question to Intel Tech Support:

Is Intel going to release an open source Linux driver for the Intel PRO/wireless 2100 LAN Mini-PCI Adapter, or provide technical specifications for the device to the Linux community?

This is the boilerplate response I received:

Thank you for contacting Intel(R) Technical Support.

Please note that Linux is supported only through ACPI enabled versions through processor.o library delivered by Intel to the major Linux distributions. A control applet is not provided.

Please check the following site for Operating system support requirements:

http://support.intel.com/support/notebook/centrino/os.htm

Please note that not all the Centrino(TM) components are compatible with Linux.

I sent an email to Intel spokesman Scott McLaughlin, but he was unable to comment further:

I assume you have read the c|net or IDG.net articles on Linux support for Centrino, which is why you have contacted me. The articles contain the extent of our comment at this time.