From 4cdc4ac63aeb7f5e17c42ad3317978bd31e1fde2 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Fri, 30 Jul 2021 23:00:10 +0200 Subject: [PATCH] Fallback to other output modes if preferred mode fails Sometimes the preferred mode is not available due to hardware constraints (e.g. GPU or cable bandwidth limitations). In these cases it's better to fallback to lower modes than to end up with a black screen. --- sway/config/output.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/sway/config/output.c b/sway/config/output.c index 7d0ed395..6224fc10 100644 --- a/sway/config/output.c +++ b/sway/config/output.c @@ -357,8 +357,26 @@ static void queue_output_config(struct output_config *oc, set_mode(wlr_output, oc->width, oc->height, oc->refresh_rate, oc->custom_mode == 1); } else if (!wl_list_empty(&wlr_output->modes)) { - struct wlr_output_mode *mode = wlr_output_preferred_mode(wlr_output); - wlr_output_set_mode(wlr_output, mode); + sway_log(SWAY_DEBUG, "Set preferred mode"); + struct wlr_output_mode *preferred_mode = + wlr_output_preferred_mode(wlr_output); + wlr_output_set_mode(wlr_output, preferred_mode); + + if (!wlr_output_test(wlr_output)) { + sway_log(SWAY_DEBUG, "Preferred mode rejected, " + "falling back to another mode"); + struct wlr_output_mode *mode; + wl_list_for_each(mode, &wlr_output->modes, link) { + if (mode == preferred_mode) { + continue; + } + + wlr_output_set_mode(wlr_output, mode); + if (wlr_output_test(wlr_output)) { + break; + } + } + } } if (oc && (oc->subpixel != WL_OUTPUT_SUBPIXEL_UNKNOWN || config->reloading)) {