Re: [Linux-fbdev-devel] LCD scaling type

[Antonino D. <ad...@po...>]

On Sat, 2003-01-11 at 03:42, Benjamin Herrenschmidt wrote:
> Hi !
> 
> When setting a mode on an LCD display that is not exactly the
> native mode of that display, we can, on some chips, setup a
> scaler. However, most of the time, we have 2 difference choices
> for setting up this scaler: It can preserve or not preserve
> the aspect ratio. A typical example is the titnium powerbook's 1152x768
> mode. If I set it to 1024x768, I can get either horizontal scaling (not
> preserving aspect ratio) or no scaling with black bars on left & right
> (preserving aspect ratio).
> 
> While in most case you actually want to preserve the aspect ratio, it
> would still I beleive make sense to let the user choose it. 
> 
> Could we define one of the reserved fields in fb_var_screeninfo as
> beeing a "flags" field for such things ? There are a couple of other
> things that we may want to stuff into such a bitfield later, I'd suggest
> reserving one 32 bits field for such flags.
> 

I second to this.  It's useful to have an extra field in
fb_var_screeninfo for drivers to play around.  It's like an extension
field and its main use is to expose a hardware capability which is
uncommon enough to warrant generic support.  It's meaning will vary from
driver to driver.  

I also have a couple of things that come to mind (like switching from
truecolor to directcolor and vice versa without rebooting).  I currently
use var->nonstd which is probably not the the right thing to do.

Tony