Messages in this thread | | | Date | Tue, 10 Nov 2020 09:00:05 +0000 | From | Paul Cercueil <> | Subject | Re: [PATCH] drm/ingenic: ipu: Search for scaling coefs up to 102%
of?? the screen |
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Le mar. 10 nov. 2020 à 9:56, Sam Ravnborg <sam@ravnborg.org> a écrit : > Hi Paul, > On Tue, Nov 10, 2020 at 08:50:22AM +0000, Paul Cercueil wrote: >> Hi, >> >> Le sam. 7 nov. 2020 à 20:33, Sam Ravnborg <sam@ravnborg.org> a >> écrit : >> > Hi Paul. >> > >> > On Thu, Nov 05, 2020 at 08:39:05AM +0000, Paul Cercueil wrote: >> > > Increase the scaled image's theorical width/height until we >> find a >> > > configuration that has valid scaling coefficients, up to 102% >> of the >> > > screen's resolution. This makes sure that we can scale from >> almost >> > > every resolution possible at the cost of a very small >> distorsion. >> > > The CRTC_W / CRTC_H are not modified. >> > > >> > > This algorithm was already in place but would not try to go >> above >> > > the >> > > screen's resolution, and as a result would only work if the >> CRTC_W / >> > > CRTC_H were smaller than the screen resolution. It will now try >> > > until it >> > > reaches 102% of the screen's resolution. >> > > >> > > Signed-off-by: Paul Cercueil <paul@crapouillou.net> >> > >> > Looks like the patch does what the descriptions says. >> > So in other words - look OK to me. I am not confident enogh for a >> r-b >> > but my code reading is enough to warrant an a-b: >> > Acked-by: Sam Ravnborg <sam@ravnborg.org> >> >> Note that this algorithm exists mostly as a band-aid for a missing >> functionality: it is not possible for userspace to request the >> closest mode >> that would encapsulate the provided one, because the GEM buffer is >> created >> beforehand. If there was a way to let the kernel tweak the mode, I >> could >> write a better algorithm that would result in a better looking >> picture. > > Could you add this nice explanation to the changelog so when we wonder > why this was done in some years we can dig up this from git history.
Sure!
-Paul
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