The screen resolution on my laptop is not reported accurately. Here's
an extract from the output of xdpyinfo (under Xwayland):
screen #0:
dimensions: 3200x1800 pixels (847x476 millimeters)
resolution: 96x96 dots per inch
The number of pixels is correct, but the size and resolution values
smack of a bogus default. The actual width of the screen (determined
with a tape measure) is about 11.5 inches (or 291 mm), which yields a
resolution of 280 dots per inch (11 dots per mm), approximately.
Most definitely _not_ 96 dpi.
Presumably X gets the size/resolution information from Wayland, which
gets it from the firmware. Here is the output from "edid-decode -s
/sys/class/drm/card0-eDP-1/edid" on the laptop:
Block 0, Base EDID:
EDID Structure Version & Revision: 1.4
Vendor & Product Identification:
Manufacturer: SDC
Model: 22602
Made in: 2015
Basic Display Parameters & Features:
Digital display
Bits per primary color channel: 8
DisplayPort interface
Maximum image size: 29 cm x 17 cm
Gamma: 2.20
DPMS levels: Standby Suspend Off
Supported color formats: RGB 4:4:4, YCrCb 4:4:4
First detailed timing includes the native pixel format and preferred
refresh rate
Color Characteristics:
Red : 0.6396, 0.3300
Green: 0.2998, 0.5996
Blue : 0.1503, 0.0595
White: 0.3134, 0.3291
Established Timings I & II: none
Standard Timings: none
Detailed Timing Descriptors:
DTD 1: 3200x1800 60.000 Hz 16:9 108.960 kHz 361.310 MHz (293 mm x
165 mm)
Hfront 48 Hsync 32 Hback 36 Hpol N
Vfront 2 Vsync 5 Vback 9 Vpol N
Manufacturer-Specified Display Descriptor (0x0f): 00 0f 00 00 00 00 00 00
00 00 00 37 82 05 46 00 '...........7..F.'
Alphanumeric Data String: 'SAMSUNG'
Alphanumeric Data String: '133YL02-C02'
Checksum: 0x41
The "29 cm x 17 cm" and "293 mm x 165 mm" values are about right (close
enough, anyway).
It looks like something is going wrong, either in Wayland or the X
server. I'd like to pin it down and get it fixed, so I'm starting by
checking Wayland.
Now, I know essentially nothing about Wayland. All I can say for sure
is that the /usr/lib64/libwayland-server file on the laptop is from
version 1.19.0 (as distributed in Fedora 34).
Can someone please tell me what to look for or what tests to run?
Thank you,
Alan Stern
