[Intel-gfx] [PATCH v3 08/20] drm/i915: fill in more mode members

[Daniel Vetter]

On Tue, Jul 14, 2015 at 01:40:45PM +0200, Maarten Lankhorst wrote:
> Op 14-07-15 om 13:21 schreef Daniel Stone:
> > Hi,
> >
> > On 14 July 2015 at 10:50, Daniel Vetter <daniel at ffwll.ch> wrote:
> >> On Mon, Jul 13, 2015 at 04:30:21PM +0200, Maarten Lankhorst wrote:
> >>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> >> Needs a summary (or just pasting relevant parts of our mail threads) about
> >> double-modesets, ways to avoid them and why exactly we ended up opting for
> >> this solution here. Especially please highlight the TYPE_DRIVER trick.
> > Actually, the original motivation for this patch when it was in my
> > branch was very different: I was seeing failures on commit because
> > hsync == vsync == 0, and also the lack of name made debugging a bit
> > more difficult. TYPE_DRIVER is new though, and separately motivated.
> >
> Oh, in my branch it was because it made me avoid modesets and to make fastboot work. But fastboot was made to work in a better way.
> 
> What about:
> "Fill in driver type, hsync, vrefresh and name.
> Those members are not read out but can be calculated from the mode."

Maybe add "Note that we mark the mode as TYPE_DRIVER to force a mismatch
with whatever mode userspace provides. This ensures we force a modeset on
the first real modeset, while avoiding spurious modesets on no-op property
changes before that (where the mode is just duplicated exactly)."
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch