From 5ad8e63ebba3d5a0730b43180b200e41eeb9409c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Noralf=20Tr=C3=B8nnes?= Date: Wed, 30 Nov 2022 20:26:54 +0100 Subject: [PATCH] drm/gud: Enable synchronous flushing by default MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit gud has a module parameter that controls whether framebuffer flushing happens synchronously during the commit or asynchronously in a worker. GNOME before version 3.38 handled all displays in the same rendering loop. This lead to gud slowing down the refresh rate for a faster monitor. This has now been fixed so lets change the default. The plan is to remove async flushing in the future. The code is now structured in a way that makes it easy to do this. Link: https://blogs.gnome.org/shell-dev/2020/07/02/splitting-up-the-frame-clock/ Suggested-by: Thomas Zimmermann Reviewed-by: Thomas Zimmermann Signed-off-by: Noralf Trønnes Link: https://patchwork.freedesktop.org/patch/msgid/20221122-gud-shadow-plane-v2-6-435037990a83@tronnes.org --- drivers/gpu/drm/gud/gud_pipe.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c index 92189474a7edb..62c43d3632d42 100644 --- a/drivers/gpu/drm/gud/gud_pipe.c +++ b/drivers/gpu/drm/gud/gud_pipe.c @@ -25,17 +25,13 @@ #include "gud_internal.h" /* - * Some userspace rendering loops runs all displays in the same loop. + * Some userspace rendering loops run all displays in the same loop. * This means that a fast display will have to wait for a slow one. - * For this reason gud does flushing asynchronous by default. - * The down side is that in e.g. a single display setup userspace thinks - * the display is insanely fast since the driver reports back immediately - * that the flush/pageflip is done. This wastes CPU and power. - * Such users might want to set this module parameter to false. + * Such users might want to enable this module parameter. */ -static bool gud_async_flush = true; +static bool gud_async_flush; module_param_named(async_flush, gud_async_flush, bool, 0644); -MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=true]"); +MODULE_PARM_DESC(async_flush, "Enable asynchronous flushing [default=0]"); /* * FIXME: The driver is probably broken on Big Endian machines. -- 2.30.2