Messages in this thread | | | Date | Tue, 10 Nov 2020 08:50:22 +0000 | From | Paul Cercueil <> | Subject | Re: [PATCH] drm/ingenic: ipu: Search for scaling coefs up to 102% of
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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.
Cheers, -Paul
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