[SOLVED] font rendering - random characters become gibberish

[RPG]

I am experiencing some very strange font rendering errors on a fresh install of Linux Mint 16 x64 MATE edition, on a Dell Latitude E6400 notebook. Typically, fonts look very nice, but what happens every now and again is that a single character (letter or number) on screen is corrupted into a weird alien gibberish character, like some pixels are obscured and other random pixels are spread around, but all within the small space where I would expect the character to be. I can't seem to capture it with a screenshot, though, so it is hard to describe. It happens in the terminal, web browser, LibreOffice, even in title bars and system menus. If I scroll the window, or highlight the text, or otherwise get the text to be redrawn, it will fix the error and the character reappears correctly. It will then appear randomly later on, somewhere else. I don't see any other patterns to the occurrence--it happens with installed system fonts and also with manually installed truetype and opentype fonts. I have noticed that the error occurs only when font smoothing (Subpixel OR Grayscale) is turned on (in Control Panel > Appearance > Fonts > Details), but fonts are super-ugly when smoothing is off. Hinting (on or off) seems to have no effect on the problem, and I made sure that the subpixel order is correct for my screen.

More information:

I am a relatively new user of Linux Mint, but with some experience with Linux and BSD.

My graphics card is an integrated Intel chipset, it reports as a Mobile Intel 4 Series Chipset, but I am a little confused about its terminology when it comes to driver files--the chipset is sometimes referred to as a GM45 chipset, or the graphics specifically as GMA X4500 graphics, or sometimes the driver is listed as i9xx, i915, or i965, even though I don't think that is my exact hardware model.

I searched Synaptic for Intel related drivers. I had the "xserver-xorg-video-intel" package installed, and I updated it to the latest version 2:2.99.904, and it did not help. Other than that, and the rendering settings in the Appearance menu, I have not fiddled with any drivers or font settings.

Here is some more video hardware information:

Code: Select all

sudo lshw -c video
  *-display:0             
       description: VGA compatible controller
       product: Mobile 4 Series Chipset Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 07
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:44 memory:f6c00000-f6ffffff memory:e0000000-efffffff ioport:ef98(size=8)
  *-display:1 UNCLAIMED
       description: Display controller
       product: Mobile 4 Series Chipset Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2.1
       bus info: pci@0000:00:02.1
       version: 07
       width: 64 bits
       clock: 33MHz
       capabilities: pm bus_master cap_list
       configuration: latency=0
       resources: memory:f6b00000-f6bfffff

Thank you for any help!

[Godot]

For what it is worth, I have the EXACT same issue on my Lenovo T400 with the same graphics chip and the exact same lshw -c video results. In fact, that is why I showed up here.

I've played with Linux on and off over the years. This time every single thing I want to do I'm finally able to get working. Only the graphics gibberish stops this from being a perfect install.

[RPG]

Well it's at least nice to know that it isn't just me. I couldn't find any other instances of this issue on Google, perhaps because I didn't know what words to search for: "corrupted", "scrambled", "obscured" characters? I, too, feel like I've finally found a *nix desktop distribution that I can use for everything, except this one issue that continues to bother me. Does anyone else have a potential solution? If I find one, I'll be sure to post here.

[wayne128]

Hi RPG

Not you alone.
Was reported in this thread.
http://forums.linuxmint.com/viewtopic.php?f=47&t=151054

Read the thread, towards the ends there is a 'possible solution' that worked for some people.

Good luck.

[RPG]

Thank you wayne! That thread exactly describes my problem. It sounds like a common issue with Intel integrated graphics chipsets on Mint 16. Now I can add a couple more adjectives to describe the character distortions: "crumbled" and "garbled"!

I tried the fix described by koala on the third page of that thread, using the 20-intel.conf file to change to UXA graphics acceleration, and it appears to work! (At least I haven't seen the error return all afternoon.) I'm going to mark this thread "solved", because it worked for me and for others. Thanks again.