From e2e5842444c20ab57cfc74cf0c0cdeb021afbc8a Mon Sep 17 00:00:00 2001 From: Olivier Fourdan Date: Thu, 8 Aug 2024 10:07:27 +0200 Subject: [PATCH] xwayland: Report correct mode size when rootful The vidmode extension emulation in Xwayland reports the modeline based on the current mode. To do so, it searches for the mode using `xwl_output_find_mode(-1, -1)` which is supposed to return the current mode, whatever that mode is. With XRandR emulation, in rootless mode, the default value is the mode at index 0. That assumption, however is not true when running rootful. That means that the vidmode extension will always return the highest mode available, which is 5120x2880, with Xwayland running rootful: $ xwayland-run -geometry 1024x768 -- xvidtune -show "5120x2880" 1276.50 5120 5560 6128 7136 2880 2883 2888 2982 -hsync +vsync Luckily, when Xwayland is running rootful, we have the current mode size conveniently stored in dedicated fields of the xwayland output struct, so we can use that to search for the right mode being used and report that through the vidmode extension: $ xwayland-run -geometry 1024x768 -- xvidtune -show "1024x768" 63.50 1024 1064 1176 1328 768 771 775 798 -hsync +vsync That fixes legacy games using the vidmode extension and rendering at the wrong size when running within Xwayland rootful. Signed-off-by: Olivier Fourdan Part-of: --- hw/xwayland/xwayland-output.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/hw/xwayland/xwayland-output.c b/hw/xwayland/xwayland-output.c index 42569f73d..e77cc4305 100644 --- a/hw/xwayland/xwayland-output.c +++ b/hw/xwayland/xwayland-output.c @@ -404,9 +404,18 @@ xwl_output_find_mode(struct xwl_output *xwl_output, RROutputPtr output = xwl_output->randr_output; int i; - /* width & height -1 means we want the actual output mode, which is idx 0 */ - if (width == -1 && height == -1 && output->modes) - return output->modes[0]; + /* width & height -1 means we want the actual output mode */ + if (width == -1 && height == -1) { + if (xwl_output->mode_width > 0 && xwl_output->mode_height > 0) { + /* If running rootful, use the current mode size to search for the mode */ + width = xwl_output->mode_width; + height = xwl_output->mode_height; + } + else if (output->modes) { + /* else return the mode at first idx 0 */ + return output->modes[0]; + } + } for (i = 0; i < output->numModes; i++) { if (output->modes[i]->mode.width == width && output->modes[i]->mode.height == height)