Possible flickering issue due to amgpu driver when cursors are to big on X11

I'm opening this bug here cause this repo is linked to at https://en.wikipedia.org/wiki/AMDgpu(Linux_kernelmodule) and I hope this is the correct place. Should I rather go to the linux kernel mailing list or to somewhere else?

When a XCursor with a size bigger than 128x128 is set, the cursor starts to flicker. I tried it on Xfce4/xfwm4 with compositors xfwm4, picom and no compositor. I have a RX560 (the cut down version with 14 Compute Units) and I'm using a pretty up to date (linux kernel 5.17.0-rc1) amdgpu as the driver. One other person using the nvidia driver had no flickering problems when they were using that DE/WM and those compositors, that's why we concluded it's a driver problem. However, there is also no flickering when I zoom in using Alt+Mousewheel but it might be that the hardware cursor is probably disabled when I zoom in (custom cursor rendering for zoom).

Why is this a relevant problem? Color picker software like https://github.com/Soft/xcolor and https://github.com/linuxdeepin/deepin-picker sets a cuts a magnified screenshot as the cursor and for that purpose a cursor that is big enough to have the flickering problem is created. I wrote a minimal example (without error handling code to keep it short) that you can use to test whether you get the flickering. Compile & run: gcc -o cur cur.c -lX11 && ./cur And then run it once again by using ./cur 128 You can stop the program by pressing Ctrl+c

#include <X11/Xcursor/Xcursor.h>
#include <stdlib.h>
static unsigned char bits[65536];

int main(int argc, char *argv[]){
    int size = argc==2 ? size=strtol(argv[1], NULL, 10) : 256;

    Display *dpy = XOpenDisplay (NULL);
    Window root = XDefaultRootWindow(dpy);

    Cursor cursor;
    XColor color = {0,32000,32000,32000};

    for (int x = 0; x < size*size; x++) {
        bits[x] = 0xff;
    } 

    Pixmap pix = XCreateBitmapFromData(dpy, DefaultRootWindow(dpy), (char *) bits, size, size);
    cursor = XCreatePixmapCursor(dpy, pix, pix, &color, &color, 0, 0);
    XFreePixmap(dpy, pix);

    XGrabPointer(dpy, root, False, OwnerGrabButtonMask, GrabModeAsync, GrabModeAsync, None, cursor, CurrentTime);

    while(1);
}

Without a parameter it sets a filled gray rectangular cursor with a size of 256x256 that flickers partly (small black horizontal bars that seem to move a bit up/down) when the mouse is moved. When you pass a number not bigger than 128 there is no flickering.

ROCm / ROCK-Kernel-Driver

Possible flickering issue due to amgpu driver when cursors are to big on X11 #129