On Fri, 5 Mar 2004, Thomas Winischhofer wrote:
David Dawes wrote:
On Fri, Mar 05, 2004 at 01:38:06AM +0100, Thomas Winischhofer wrote:
What exactly does a video driver have to be able to do if the SupportConvert32to24 flag is set at calling xf86SetDepthBpp, provided the hardware supports, for instance, 24bpp (framebuffer depth) only?
It has to use a framebuffer layer that can do this conversion. fb can, as can xf24_32bpp (if your driver uses cfb). The s3virge driver is an example that can still be run with the xf24_32bpp method, and it does the following to figure out what to load:
case 24: if (pix24bpp == 24) { mod = "cfb24"; reqSym = "cfb24ScreenInit"; } else { mod = "xf24_32bpp"; reqSym = "cfb24_32ScreenInit"; }
Most drivers use fb these days, and it has support for this built-in, and enabled automatically.
So it is save just to set these, I assume (since my driver uses fb). (Just wondered why the *driver* and not the layer taking care of this has to (not) set these.)
Do you mean the flag? The layer above does not know whether
or not the driver/HW supports a 24 bpp framebuffer. The "nv" driver,
for example, does not.
Whether or not the hardware does support 24bpp (framebuffer depth, not talking about color depth) should be determined by setting/clearing SupportXXbpp. Why the *driver* needs to set "SupportConvert...." is beyond me. My understanding is that the respective fb layer should take care of this (if supported) based on SupportXXbpp (especially since the *driver* does not need to care about this, as David told me. It just depends on what layer I choose for above the driver level).
But anyway, my question was answered. Seems to be save to set this obsure SupportConvert32to24 flag if using the generic fb layer.
Thomas
-- Thomas Winischhofer Vienna/Austria thomas AT winischhofer DOT net http://www.winischhofer.net/ twini AT xfree86 DOT org _______________________________________________ Devel mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/devel
