| Summary: | [RADEON:KMS:RV200:M7:DDX] inferior output using external VGA with radeon mobility m7 laptop | ||||||||||||||||||||||||
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| Product: | xorg | Reporter: | Clint Adams <clint> | ||||||||||||||||||||||
| Component: | Driver/Radeon | Assignee: | xf86-video-ati maintainers <xorg-driver-ati> | ||||||||||||||||||||||
| Status: | RESOLVED INVALID | QA Contact: | Xorg Project Team <xorg-team> | ||||||||||||||||||||||
| Severity: | normal | ||||||||||||||||||||||||
| Priority: | medium | CC: | kibi | ||||||||||||||||||||||
| Version: | unspecified | ||||||||||||||||||||||||
| Hardware: | x86 (IA32) | ||||||||||||||||||||||||
| OS: | Linux (All) | ||||||||||||||||||||||||
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| i915 platform: | i915 features: | ||||||||||||||||||||||||
| Attachments: |
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Description
Clint Adams
2011-03-09 13:48:15 UTC
Created attachment 44284 [details]
uname output
Created attachment 44285 [details]
dmesg output
Created attachment 44286 [details]
Xorg log
(In reply to comment #4) > On various laptops with radeon cards, the LVDS display is fine, but the font > rendering varies from blurry to spastic on an external display, and sometimes > the color balance is affected. Can you attach photos highlighting the problem? Is the external display an LCD as well, or a good old fashioned CRT? Oh, and can you attach the output of xrandr --verbose? Also please list GPU you tested with and kind of video output (VGA,DVI,HDMI,DISPLAY PORT) Created attachment 44325 [details]
photo of screen
Created attachment 44326 [details]
photo of screen
Created attachment 44327 [details]
photo of screen
Created attachment 44328 [details]
photo of screen
Created attachment 44329 [details]
photo of screen
Created attachment 44330 [details]
photo of screen
Created attachment 44331 [details]
xrandr --verbose
Attached 3 pairs of photos comparing the good LVDS (LCD) screen versus the external LCD monitor connected to the VGA port on the laptop, as well as xrandr --verbose. I don't understand the GPU question. In addition to the card I listed in the first submission, the problem also occurs with a laptop containing ATI Technologies Inc Radeon RV250 [Mobility FireGL 9000] This problem occurs with a number of laptop and external monitor combinations (though all are LCD). It does not occur when using the driver from lenny with the same kernel, hardware, and monitor. It's kinda hard to tell from the photos, but I think the text might be using sub-pixel anti-aliasing. Does disabling that help? (In reply to comment #17) > It's kinda hard to tell from the photos, but I think the text might be using > sub-pixel anti-aliasing. Does disabling that help? Unless it's the default, it is not enabled except for the Korean fonts in ttf-unfonts-core and ttf-unfonts-extra. Removing this does change the font rendering on the LVDS, but appears to have no effect on the VGA. If it's the default, then I probably don't understand fontconfig well enough to ensure that it's disabled. You can tell by inspecting the aliased pixels of black text on white background. If any of them aren't gray (i.e. not all of their colour components are equal), that's sub-pixel anti-aliasing. (In reply to comment #19) > You can tell by inspecting the aliased pixels of black text on white > background. If any of them aren't gray (i.e. not all of their colour components > are equal), that's sub-pixel anti-aliasing. There are varying shades of pixels along the edges of the letters. If I disable "Smoothing" and "Hinting" in gnome-appearance-properties, it becomes strictly black and white, and looks much worse on both screens. (In reply to comment #20) > If I disable "Smoothing" and "Hinting" in gnome-appearance-properties, it > becomes strictly black and white, and looks much worse on both screens. Disabling 'smoothing' disables anti-aliasing. If it's set to 'grayscale' as opposed to 'Subpixel (LCDs)', sub-pixel anti-aliasing should be disabled. Or you could just compare the example text in the dialogue to see the effect of each setting. When sub-pixel anti-aliasing is enabled, you may also want to play with the subpixel orders at the bottom of that dialogue. > Disabling 'smoothing' disables anti-aliasing. If it's set to 'grayscale' as > opposed to 'Subpixel (LCDs)', sub-pixel anti-aliasing should be disabled. Or > you could just compare the example text in the dialogue to see the effect of > each setting. In that case it was not enabled; I believe the setting was called "Best shape" or something like that. > When sub-pixel anti-aliasing is enabled, you may also want to play with the > subpixel orders at the bottom of that dialogue. We'll give that a try on Monday. Is there anything else that will help isolate the bug? > When sub-pixel anti-aliasing is enabled, you may also want to play with the
> subpixel orders at the bottom of that dialogue.
I cannot detect any variation between these.
Mass closure: This bug has been untouched for more than six years, and is not obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases. |
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