Bug 34682

About 3 years ago I wrote bug ID #15201 and followed it up with a simple patch to the Intel xorg driver to enable the use of LVDS devices which expect pixel data formatted as 24 bits (as opposed to the usual 18 bit pixel data).

Now 3 years later, the project which triggered #15201 has moved on to a much more recent Intel GPU and with that we've been unsurprisingly forced up to a more recent kernel, DRI driver, etc.  And that also required a shift to a much later Intel xorg driver that no longer does mode switching in user space - instead it's using kernel mode setting (KMS).  It appears that the fix from #15201 was a casualty of the move to KMS, now that the old UMS code - which had that fix - has since been removed from the userspace Intel xorg driver.  So now I'm stuck once again with a 24 bit LVDS display device that won't work in Linux with the Intel driver.

I've examined drivers/gpu/dri/i915 in kernel 2.6.38-rc5 and I see similar old code in intel_display.c that predates the fix I had made 3 years ago in the userspace side.  I believe I can make the same fix again here, except the switch controlling this will probably now have to be a kernel module option instead of an option to the xorg driver itself.

Are there any objections to me (re)creating this fix and submitting it here for inclusion into the kernel?  Or is it possible - even likely - that somebody has already done this a different way and I just haven't figured it out yet?

  -Mike Isely
   isely@pobox.com