Running The OMAPDRM On Ubuntu 12.04 LTS

Besides Ubuntu 12.04 on ARMv7 being much faster, thanks to hard-float and other improvements, the Texas Instruments OMAP DRM driver is also available to provide a KMS experience for some hardware.

The Texas Instruments OMAP DRM driver has been available since last year as a DRM/KMS driver for Texas Instruments' OMAP platform. The OMAPDRM driver doesn't provide any graphics acceleration support, but does implement GEM memory management and supports HDMI, DVI, and LCD panels. The display hardware is programmed via the DSS2 driver similar to the other OMAP kernel display drivers (V4L2 and fbdev).

Texas Instruments can't provide any open-source 3D acceleration support for OMAP since they're using a PowerVR SGX core, which as most Phoronix readers know is a big bloody mess that's tied up by Imagination Technologies. The OMAPDRM driver has made it into the mainline kernel as a simple DRM driver for the OMAP display hardware, similar to the Samsung Exynos DRM driver.

With the driver now in the mainline Linux kernel, with Ubuntu 12.04 LTS on the Linux 3.2 kernel is the first Ubuntu release where this OMAPDRM driver is available. If you're booting Ubuntu ARM on supported OMAP hardware, this DRM driver is now brought up by default. This particular testing was done from a PandaBoard ES that's using the Texas Instruments OMAP4460 SoC.

When booting the Ubuntu 12.04 OMAP4 pre-installed image for the first time on the PandaBoard ES, the KMS-empowered Plymouth quickly came up. When it came to hitting the X.Org Server and the Unity 2D desktop, the xf86-video-fbdev driver was loaded as the DDX with the omapdrm kernel driver underneath.

The OMAPDRM driver did correctly mode-set by default to 1920 x 1200 over HDMI for the PandaBoard ES. Unfortunately using Ubuntu 12.04 with this unaccelerated stack on the OMAP4460 with the Unity 2D desktop was rather sluggish. Moving and launching windows was slow and far from being a fluid experience. There is also a xf86-video-omap DDX driver that is compatible with the OMAPDRM, but that wasn't found used by default in Ubuntu 12.04.

For those wanting to know what the desktop experience is like without proper acceleration, there are OMAPDRM benchmarks on OpenBenchmarking.org with GTK, X11, and Cairo tests.

In Ubuntu 12.04 via jockey-gtk for the Texas Instruments OMAP ARMv7 hardware there is a proprietary PowerVR SGX graphics driver available for the OMAP4... It's a PowerVR driver catered to the TI OMAP4, which like most PVR drivers, was a busted mess.

When this OMAP4 PowerVR SGX driver was enabled in Ubuntu 12.04, the experience was worse. Mode-setting was not done correctly for the 1920 x 1200 HDMI display, acceleration was messed up, and there were plenty of errors. It's no wonder why Rob Clark, the Texas Instruments Linux developer mostly responsible for the OMAPDRM code, loves open-source drivers so much that he even works on reverse-engineering and open-source driver writing for TI's competitors: An Open-Source Graphics Driver For Snapdragon.

PowerVR Linux support remains a big mess with no signs of corrections coming soon, besides Intel at least dropping PowerVR in future products: Intel Valley View: Atom SoC With Ivy Bridge Graphics. While PowerVR SGX is especially common in ARM SoCs, Linux consumers should try to avoid this crap at all possible costs. But in terms of the OMAPDRM driver for Ubuntu 12.04, at least the display hardware on the OMAP4 is working fine.