On Tue, Mar 05, 2013 at 04:47:09PM +0800, Greg KH wrote > On Tue, Mar 05, 2013 at 02:01:31AM -0500, Walter Dnes wrote: > > On Mon, Mar 04, 2013 at 03:44:33PM -0100, Carlos Silva wrote > > > On Mon, Mar 4, 2013 at 3:28 PM, Walter Dnes <waltd...@waltdnes.org> wrote: > > > > > > > I'm not a C programmer, let alone a developer, so this may be a stupid > > > > question, but here goes... has anyone ever tried doing a HAL (Hardware > > > > Abstraction Layer) to present a reasonably stable interface to binary > > > > video drivers? Think of it as a shim translating a "pseudo-API" into > > > > "the real API" that the kernel exposes directly. Surely, we can do > > > > better than VESA. Give drivers 2 options... > > > > 1) direct kernel access like now > > > > 2) access via the HAL/shim > > > > > > > > > Just read this file and you'll have the answer: > > > /usr/src/linux/Documentation/stable_api_nonsense.txt > > > > Thanks. That was an eye-opener. If user-space drivers are really > > that slow, we may as well stick with VESA as a fallback. > > Ok, I'll bite, What do you mean by that? Where does the > stable_api_nonsense.txt file talk about userspace drivers? > > greg "I wrote that file" k-h
My statement was a general response to the entire thread. Sorry, I should've retitled it [REDUX whatever] * stable_api_nonsense.txt explained lack of a stable *KERNEL* api * Duncan's message talked about slow *USERSPACE* API... > Of course it's possible to implement a userspace driver that > wouldn't have the same issues as it'd use the stable userspace API, > but that's generally accepted to be far too high a performance cost > for graphics drivers, regardless of the kernel involved (MS tried > it too for stability reasons and gave up at the performance penalty > they were taking). So between your file, and Duncan's message, I saw that... 1) a stable kernel API is not possible 2) a userspace API is too slow. I apologize again for the vagueness in my previous reply. -- Walter Dnes <waltd...@waltdnes.org> I don't run "desktop environments"; I run useful applications
