The video= parameter of the DRM drivers supports some additional flags that
the normal fb drivers do not have. They also allow to limit these flags to
specific outputs. Both things were previously undocumented.
Also the parsing of the line had some oddities:
-A lot of misplaced options were silently ignored or partly rejected instead
of stopping the parsing immediately
-The 'R' option is documented to follow the 'M' option if specified. It is not
documented that 'M' is needed to specify 'R' (also this is the case for normal
fb drivers). In fact the code is correct for normal fb drivers but wrong for
DRM ones.
The old code allowed 'R' only _before_ 'M' (since it parses backwards) and only
if 'M' is given at all which is not needed for the DRM drivers.
-the margins option ('m') was parsed but later ignored even if the later
functions support it.
-specifying multiple enable options at the same time did not lead to an error.
-specifying something bogus for horizontal resolution (i.e. other things as
digits) did not lead to an error but an invalid resolution was used.
If any errors are encountered the position of the faulting string is now
printed to the user and the complete mode is ignored. This gives much
more consistent error behaviour.
I also removed some useless assignments and changed the local flag variables
to be bool.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Add names of drivers converted to "mode_option" parameter.
This is one step toward changing all fb drivers to have common "mode_option"
parameter.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Coordinated Video Timings (CVT) is the latest standard approved by VESA
concerning video timings generation. It addresses the limitation of GTF which
is designed mainly for CRT displays. CRT's have a high blanking requirement
(as much as 25% of the horizontal frame length) which artificially increases
the pixelclock. Digital displays, on the other hand, needs to conserve the
pixelclock as much as possible. The GTF also does not take into account the
different aspect ratios in its calculation.
The new function added is fb_find_mode_cvt(). It is called by fb_find_mode()
if it recognizes a mode option string formatted for CVT. The format is:
<xres>x<yres>[M][R][-<bpp>][<at-sign><refresh>][i][m]
The 'M' tells the function to calculate using CVT. On it's own, it will
compute a timing for CRT displays at 60Hz. If the 'R' is specified, 'reduced
blanking' computation will be used, best for flatpanels. The 'i' and the 'm'
is for 'interlaced mode' and 'with margins' respectively.
To determine if CVT was used, check for dmesg for something like this:
CVT Mode - <pix>M<n>[-R], ie: .480M3-R (800x600 reduced blanking)
where: pix - product of xres and yres, in MB
M - is a CVT mode
n - the aspect ratio (3 - 4:3; 4 - 5:4; 9 - 16:9, 15:9; A - 16:10)
-R - reduced blanking
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Rolf Eike Beer