Description of problem: I have a mageia 7 installation on a computer attached to a monitor using a VGA KVm switch. When I switch to a different computer, and then back to mageia, sometimes the graphics driver switches to a different resolution/frequency that the the display can't display. I have never observed this using mageia 4-6. Version-Release number of selected component (if applicable): How reproducible: 100% Steps to Reproduce: 1. install mageia 7 2. switch to a different computer via KVm switch 3. sometimes when switching back to mageia, screen goes to undisplable resolution/frequency. The way I deal with the problem is very brute force. I create a new account, backup all the files in the corrupted account, restore from the new account and then restore the files I care about from my backup. Then, the graphics configuration works fine. I am now afraid to switch away from the mageia computer while the GUI is running.
Sorry for the grief you are having. The main complaint is clear: the screen sometimes becomes entirely corrupt - invalid resolution/frequency - after being switched to a different computer, then back to Mageia. But the rest is not at all clear; a corrupted screen has nothing to do with a corrupted (on disc) account. > I create a new account, backup all the files in the corrupted account, > restore from the new account and then restore the files I care about from > my backup. Then, the graphics configuration works fine. What do you mean by 'corrupted account'? That which is active when the screen corruption happens? What files do you backup from that account to the extra account? Everything in $HOME ? Do you do this (and what follows) from a virtual console? What do you mean by "restore from the new account"? Restore what to where? What files "I care about" do you then restore to the main user? How can they be different from what you backed up? How do you get then back to a working GUI for the main user? Ctrl/Alt/F1 ?
CC: (none) => lewyssmith
The screen does not become corrupt, it switches to a mode not supported by the monitor. Specifically, I have a 4k monitor with multiple inputs. My mageia computer is connected to a VGA input. The VGA resolution is 1920x1080. Usually I can use the KVM switch without issue. However, several times the video mode gets switched to 4k, which is not supported by VGA. At this point, I have no usable video. I can control-alt-backspace to get back to a command line, but if I say 'startx' it again tries to do 4k graphics. When I say 'corrupted account' I mean an account with a corrupted video resolution specification that the monitor does not support. I suspect the file may be the file in .local/share/kscreen, but that is just a guess. As for backup, using the root account, I create a new account. As root, I copy the files I care about from the original account to the new account. I then remove all files in $HOME for the original account, and copy everything from $HOME in the new account back to the original account. When I boot, I don't start X. I boot to the command line. This is because I don't always need X, and I have had historical issues with X working well. The way I get a working GUI is by copying *everything* from new $HOME to the emptied original $HOME.
Thank you for your explanations. You reveal some interesting things. It looks as if you are using Plasma. If this is the case, can you say whether the problem happens with a different desktop? > the video mode gets switched to 4k, which is not supported by VGA Where does it get switched (in the KVM box?)? How do you know? > I suspect the file may be the file in .local/share/kscreen/ This looks a good guess, from its content (on my box): $ cat .local/share/kscreen/8bf072fe4b4e69e8179297f518b39d01 [ { "enabled": true, "id": "8dcc334cadf115d4ad3d94b8cbb511a1", "metadata": { "fullname": "xrandr-S19B150-HMAC601418", "name": "VGA-0" }, "mode": { "refresh": 59.7895393371582, "size": { "height": 768, "width": 1366 } }, "pos": { "x": 0, "y": 0 }, "primary": true, "rotation": 1, "scale": 1 } ] Have you ever tried restoring *just* it from the new user account? Or easier, perhaps, for diagnostics, copying it in its host account before switching away. Your complicated workaround suggests that something is being changed in the main $HOME directory, like the file above. Have you looked for *any* such change between switching from & back to Mageia? Sorry for the questions, to do with where to pass this bug.
I am running the plasma desktop. I have not tried another desktop. When things go bad, it happens when I switch from a different computer to the mageia computer via the KVM seitch. Rather than seeing the desktop, I get an error message from the display (a philips 43" 4k) which says the resolution is set to 3840 × 2160 and some frequency that I don't recall offhand. Since VGA doesn't support that, of course it can't be displayed. I have not tried just restoring the file in .local/share/kscreen. The issue has happened twice to me, and it is a bit annoying. On another occasion, while switching back to mageia with the KVM switch, the resolution went to some really low resolution, such as 640 x 480. IIRC I was able to recover that by using the 'settings' applet. I only made a spare user the last time the issue happened. I am used to much older versions of mageia / mandrake / mandriva, and I was looking for an x.org or some other legacy named file. Having the file in .local/share/kscreen with what looks like a random name didn't make it easy to find. I suspect the issue may be related to the code to process dynamically adding / removing a display from a running system, but that is just a guess. I know it isn't very common to have a KVM switch, but it something that should be supported. I am pretty sure using a KVM switch worked fine with mageia 4, 5, and 6, as well as many versions of fedora, and microsoft windows.
> I know it isn't very common to have a KVM switch, but it something that > should be supported Quite right; it is 'normal' if unusual. I am still unclear about who sets the video parameters on switching computers: the switch, or the destination system. Assigning to Thierry for X11-server.
Assignee: bugsquad => thierry.vignaudCC: lewyssmith => (none)Source RPM: (none) => x11-server-1.20.7-1.mga7.src.rpm
VGA has something called EDID (Extended Display Identification Data) which describes the video modes supported. The video driver is supposed to respect that, and use a supported mode. this is how a VGA monitor gets identified as a Philips model 123, rather than generic monitor. My monitor is correctly identified, so EDID is working through the KVM switch.
It happened again today. The file in .local/share/kscreen is getting corrupted. I moved the bad one out of the way, and restarted the x window manager. I diffed the bad file with the one just created. Here it is: diff borked_kscreen_file .local/share/kscreen/4a36931759d09f1c7755d364732fb8fd 10c10 < "refresh": 120.00031280517578, --- > "refresh": 60, The resolution is 1920 x 1080, and a generic VGA LCD display. Somehow the bad file gets the refresh value of 120 hz. It would be great to get this problem fixed.
Mageia 7 is EOL since July 1st 2021. There will not have any further bugfix for this release. You are encouraged to upgrade to Mageia 8 as soon as possible. @reporter, if this bug still apply with Mageia 8, please let us know it. @packager, if you work on the Mageia 7 version of your package, please check the Mageia 8 package if issue is also present. In this case, please fix the Mageia 8 version instead. This bug report will be closed OLD if there is no further notice within 1st September 2021.
Hi bug reporter and hi assignee and others involved, Please reopen this bug report if it is still valid for Mageia 8 or 9(cauldron), and change "Version:" in the upper left of this report accordingly. This report is being closed as OLD because it was filed against Mageia 7, for which support ended on June 30th 2021. Thanks, Marja
Resolution: (none) => OLDStatus: NEW => RESOLVED