On Tue, 30 Jun 2009 11:46:04 +0200 "David Müller (ELSOFT AG)" <d.muel...@elsoft.ch> wrote:
> Hello > > While testing Linux kernel 2.6.30 and the i915 driver, i noticed that > GPIOA is hardwired to be used as the only possible CRTDDC bus. > > code snippet from drivers/gpu/drm/i915/intel_crt.c: > > 441 /* Set up the DDC bus. */ > 442 intel_output->ddc_bus = intel_i2c_create(dev, GPIOA, > "CRTDDC_A"); 443 if (!intel_output->ddc_bus) { > > > Using the VGA BIOS configuration program, the I2C bus used for CRTDDC > can be changed according to HW requirements (especially if a DVI-I > connector is present on the board), so the above restriction brakes > all platforms not using GPIOA as their CRTDDC bus. > > The Xorg Intel graphics driver is at least a little bit more flexible > by probing GPIOD + GPIOE as well for possible attached CRT devices, > but i'm not sure if this really sufficient in all cases. > > Shouldn't the i915 driver use the information provided by the VBT > ("crt_ddc_gmbus_pin" field in the "bdb_general_definitions" block) to > figure out which I2C to use for CRTDDC? Yes, you're probably right. Cc'ing Ma Ling, who's been working in this area, for comment. -- Jesse Barnes, Intel Open Source Technology Center ------------------------------------------------------------------------------ -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel