Opened 10 years ago

Last modified 5 months ago

#5214 assigned bug

[Intel_extreme] Wrong BPP on Intel GMA 950

Reported by: HaikuBot Owned by: nobody
Priority: normal Milestone: R1/beta2
Component: Drivers/Graphics/intel_extreme Version: R1/Development
Keywords: Cc: lurohh@…
Blocked By: #7662 Blocking: #4797
Has a Patch: no Platform: All

Description

Greeting.

I found that bug when try set this wallpaper (http://www.artofadambetts.com/images/postgraphics/downloads/desktopbgs/beoriginal-1920.png). On my laptop gradient not smooth as it should be. See photos.

I were try switch to VESA and see what be. In VESA with BPP 32 bits - gradient smooth as it should be. But with BPP 16 bits - gradient displayed exactly as on photos. So I can make conclusion that intel_extreme driver set incorrect BPP.

Attachments (7)

16bits_photo_1.jpg (383.6 KB) - added by HaikuBot 10 years ago.
16bits_photo_2.jpg (395.3 KB) - added by HaikuBot 10 years ago.
16bits_screen_preflet.png (89.2 KB) - added by HaikuBot 10 years ago.
Screen preflet screenshot
listdev.txt (3.4 KB) - added by HaikuBot 10 years ago.
syslog.txt (89.3 KB) - added by HaikuBot 10 years ago.
VESA_16bits_photo_.jpg (398.3 KB) - added by HaikuBot 10 years ago.
VESA_32bits_photo_.jpg (426.5 KB) - added by HaikuBot 10 years ago.

Download all attachments as: .zip

Change History (23)

Changed 10 years ago by HaikuBot

Attachment: 16bits_photo_1.jpg added

Changed 10 years ago by HaikuBot

Attachment: 16bits_photo_2.jpg added

Changed 10 years ago by HaikuBot

Attachment: 16bits_screen_preflet.png added

Screen preflet screenshot

Changed 10 years ago by HaikuBot

Attachment: listdev.txt added

Changed 10 years ago by HaikuBot

Attachment: syslog.txt added

comment:1 Changed 10 years ago by stippi

What is most likely the problem is that you actually have a 16 bpp panel. Graphics chips can be programmed to subtly dither the output by varying the pixel brightness forth and back every other refresh. We found this out last BeGeistert when Rudolf fixed the nvidia driver to turn on this exact feature. What I am guessing is that when you run in VESA mode, the feature is automatically turned on through your VESA-BIOS, while when running with the native intel driver, it is not turned on yet.

comment:2 Changed 10 years ago by axeld

I can't really see much difference between the two images (but I'm using the Intel Extreme driver as well ;-)).

Anyway, this probably just means that your *display* does not support more colors properly. I would assume VESA enables some panel dithering mode that I don't use in the driver.

I haven't seen anything like this in the docs, but I didn't search for this particular thing either, yet.

Changed 10 years ago by HaikuBot

Attachment: VESA_16bits_photo_.jpg added

Changed 10 years ago by HaikuBot

Attachment: VESA_32bits_photo_.jpg added

comment:3 Changed 10 years ago by HaikuBot

Attached photos with VESA.

Under Windows, Linux and OpenBSD I never seen anything like this.

comment:4 Changed 10 years ago by luroh

Cc: lurohh@… added

comment:5 in reply to:  2 Changed 10 years ago by HaikuBot

Replying to axeld:

I haven't seen anything like this in the docs, but I didn't search for this particular thing either, yet.

In which docs? Maybe I can seach for dithering mode in this docs?

comment:6 Changed 10 years ago by axeld

See http://intellinuxgraphics.org/documentation.html - there are a couple of docs that should cover the chipset in question to a degree.

comment:7 Changed 9 years ago by luroh

Blocking: 4797 added

(In #4797) Closing as duplicate of #5214 which has more info and better pictures.

comment:8 Changed 9 years ago by mr.Noisy

Same problem with Intel Mobile 945GME. Unsmooth gradient in glow around HAIKU text in default background on real hardware compared to VirtualBox.

comment:9 Changed 9 years ago by humdinger

Maybe this is the same issue I had with my nvidia 7600go, see #4411, which was fixed by introducing dithering in hrev33653.

I also have a netbook with an i945GME. It shows the same "banding" when displaying a gradient. When taking a screenshot and looking at it on my other computer, the gradient is smooth. Maybe it's the same thing.

comment:10 Changed 9 years ago by HaikuBot

Here something about enabling\disabling ditherind mode.

comment:11 Changed 8 years ago by pulkomandy

Milestone: R1/alpha3R1

This is valid, but the system is useable nonetheless. Removing of alpha3 milestone.

comment:12 Changed 8 years ago by scottmc

Blocking: 7662 added

comment:13 Changed 2 years ago by axeld

Owner: changed from axeld to nobody
Status: newassigned

comment:14 Changed 10 months ago by pulkomandy

Milestone: R1R1/beta2

comment:15 Changed 5 months ago by waddlesplash

Please retest after hrev53040.

comment:16 Changed 5 months ago by waddlesplash

Blocked By: 7662 added
Blocking: 7662 removed
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