Bug 133926 – Virtual desktop does not always follow cursor

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Kimmo Sundqvist 2006-05-21 00:40:29 UTC]

I put "Virtual 2304 1728" into the screen section of xorg.conf. My card is a Matrox G400 and this is an average Pentium III class machine.

Problem is that the virtual scrolling is often jerky or does not happen at all. Sometimes the viewport stays in place when I move my mouse far far outside any of its edges. I can travel with the cursor outside the viewport, and then travel back, seeing that the cursor was far out there, because it does not reappear immediately. Some times the viewport jumps all the way to where the cursor is, sometimes I must come back with the cursor and try a different direction to have the viewport scroll again.

It doesn't look like the machine was doing anything while this happens. My X is the modular version in ~x86.

This also happens: I'm at the upper right corner of my virtual desktop. I move the mouse to the lowest edge of the desktop. The viewport still shows the upper right corner. I move my mouse back, so it appears in the viewport. I then move the mouse over the left edge of the viewport.

Now, the screen suddenly jumps a bit left, and down to the bottom edge of the virtual desktop. It means, my mouse movement somehow got registered, but the viewport location does not get updated until I somehow "trigger" an update.

It is not about the machine being busy. I managed to get the cursor again to the opposite end of the virtual desktop, without the viewport following it. Any time I try this, I succeed on third or fourth try, and sometimes two to three times in a row. I can wait and count to 30 without the viewport jumping to where my cursor is. Nothing will happen until I again move the mouse and somehow "trigger" an update.

[Comment 1 Kimmo Sundqvist 2006-05-21 06:55:25 UTC]

Changing back to hardware cursor fixed the problem.  Now viewport follows cursor perfectly.  Anyway, it is a bug in the software cursor implementation.

I used software cursor by default because years ago had a problem with Matrox and HW cursor that caused the cursor to appear as a 64x64 pixel white block.  That seems fixed now, and this far HW cursor has looked the same as SW cursor.

[Comment 2 Joshua Baergen (RETIRED) 2006-05-22 08:39:33 UTC]

It'd be appreciated if you could unmask the X11R7.1 release candidate (it's pretty much 7.1 stable at this point) and see if the software cursor problem is still there.  If so, a bug should be filed at https://bugs.freedesktop.org .

[Comment 3 Donnie Berkholz (RETIRED) 2006-06-20 23:02:00 UTC]

Please reopen when you reply.

[Comment 4 Kimmo Sundqvist 2006-07-20 23:10:42 UTC]

Fixed in Xorg 7.1

[Comment 5 Joshua Baergen (RETIRED) 2006-07-21 17:36:40 UTC]

Awesome, thanks.