On Wed, Aug 22, 2018 at 09:14:08PM -0700, John Stultz wrote: > On Mon, Aug 20, 2018 at 11:44 PM, John Stultz <john.stultz@xxxxxxxxxx> wrote: > > Hey Noralf, all, > > I've been digging for a bit on the regression that this patch has > > tripped on the HiKey board as reported here: > > https://lkml.org/lkml/2018/8/16/81 > > > > The first issue was that the kirin driver was setting > > mode_config.max_width/height = 2048, which was causing errors as the > > the requested resolution was 1920x2160 (due to surfaceflinger > > requesting y*2 for page flipping). > > Hey Noralf, > Sorry, I know your probably sick of me. But I just wanted to circle > around on this little bit. So part of the issue I found earlier, was > that I'm running w/ CONFIG_DRM_FBDEV_OVERALLOC=200, to support > Surfaceflinger's request for page flipping. This is what makes the Y > resolution 2160, which runs afoul of the new max_height check of 2048 > in the generic code. > > I was checking with Xinliang, who know the kirin display hardware, > about the max_height being set to 2048 to ensure bumping it up wasn't > a problem, but he said 2048x2048 was unfortunately not arbitrary, and > that was the hard limit of the display hardware. However, with > overalloc, the 1920x2160 res fbdev should still be ok, as only > 1920x1080 is actually displayed at one time. I recently tried to clarify that max_width/height are simply the max framebuffer dimensions supported by the driver. So it's perfectly legal for a driver to declare max_height as something big that can't be scanned out in its entirety by a single plane. For i915 I'm currently working on bumping these limits to 32k-1 regardless of the hardware scanout limitations. So if you're already running with a framebuffer height >2048 and it works then it would seem to me that you could just bump this limit in the driver. -- Ville Syrjälä Intel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
