On Wed, 2017-09-27 at 09:09 +0900, Tomasz Figa wrote: > On Wed, Sep 27, 2017 at 2:32 AM, Juan A. Suarez Romero > <[email protected]> wrote: > > On Mon, 2017-09-25 at 16:25 +0900, Tomasz Figa wrote: > > > On Fri, Aug 11, 2017 at 1:31 PM, Tomasz Figa <[email protected]> wrote: > > > > On Fri, Aug 11, 2017 at 2:29 AM, Emil Velikov > > > > <[email protected]> wrote: > > > > > On 10 August 2017 at 14:59, Tomasz Figa <[email protected]> wrote: > > > > > > dri2_fallback_swap_interval() currently used to stub out swap > > > > > > interval > > > > > > support in Android backend does nothing besides returning EGL_FALSE. > > > > > > This causes at least one known application (Android Snapchat) to > > > > > > fail > > > > > > due to an unexpected error and my loose interpretation of the EGL > > > > > > 1.5 > > > > > > specification justifies it. Relevant quote below: > > > > > > > > > > > > The function > > > > > > > > > > > > EGLBoolean eglSwapInterval(EGLDisplay dpy, EGLint interval); > > > > > > > > > > > > specifies the minimum number of video frame periods per buffer > > > > > > swap > > > > > > for the draw surface of the current context, for the current > > > > > > rendering > > > > > > API. [...] > > > > > > > > > > > > The parameter interval specifies the minimum number of video > > > > > > frames > > > > > > that are displayed before a buffer swap will occur. The interval > > > > > > specified by the function applies to the draw surface bound to > > > > > > the > > > > > > context that is current on the calling thread. [...] interval is > > > > > > silently clamped to minimum and maximum implementation dependent > > > > > > values before being stored; these values are defined by > > > > > > EGLConfig > > > > > > attributes EGL_MIN_SWAP_INTERVAL and EGL_MAX_SWAP_INTERVAL > > > > > > respectively. > > > > > > > > > > > > The default swap interval is 1. > > > > > > > > > > > > Even though it does not specify the exact behavior if the platform > > > > > > does > > > > > > not support changing the swap interval, the default assumed state > > > > > > is the > > > > > > swap interval of 1, which I interpret as a value that > > > > > > eglSwapInterval() > > > > > > should succeed if called with, even if there is no ability to > > > > > > change the > > > > > > interval (but there is no change requested). Moreover, since the > > > > > > behavior is defined to clamp the requested value to minimum and > > > > > > maximum > > > > > > and at least the default value of 1 must be present in the range, > > > > > > the > > > > > > implementation might be expected to have a valid range, which in > > > > > > case of > > > > > > the feature being unsupported, would correspond to {1} and any > > > > > > request > > > > > > might be expected to be clamped to this value. > > > > > > > > > > > > Fix this by defaulting dri2_dpy's min_swap_interval, > > > > > > max_swap_interval > > > > > > and default_swap_interval to 1 in dri2_setup_screen() and let > > > > > > platforms, > > > > > > which support this functionality set their own values after this > > > > > > function returns. Thanks to patches merged earlier, we can also > > > > > > remove > > > > > > the dri2_fallback_swap_interval() completely, as with a singular > > > > > > range > > > > > > it would not be called anyway. > > > > > > > > > > > > v2: Remove dri2_fallback_swap_interval() completely thanks to higher > > > > > > layer already clamping the requested interval and not calling > > > > > > the > > > > > > driver layer if the clamped value is the same as current. > > > > > > > > > > > > > > > > Not every driver is EGL 1.5, although the 1.4 spec has exact same > > > > > text. > > > > > > > > > > Reviewed-by: Emil Velikov <[email protected]> > > > > > > > > > > We could have this in stable, but will need a clamp like v1 since > > > > > Eric's rework did not land there. > > > > > Gents, how do you feel on the topic? > > > > > > > > FWIW, Eric's patches applied cleanly onto our chromium branch, which > > > > was based on something not very far away from what 17.2 branched at. > > > > If for some reasons we prefer to avoid further cherry picks, we can go > > > > with my v1 for stable, which doesn't depend on them. > > > > > > Gentle ping. :) > > > > > > > Tomasz, didn't Chad and Tapani granted a R-b?
BTW, as this v2 requires Eric patches that are not in 17.2 stable branch, I'll cherry-pick v1 instead for stable release, as suggested. If you think this shouldn't go to stable, let me know. > That's right. I'd appreciate if someone committed it to the tree, > though. (Sorry, I haven't managed to get through the commit access > application yet.) > > Best regards, > Tomasz > _______________________________________________ > mesa-stable mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/mesa-stable _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
