Information for Tseng Chipset Users : linear memory base address (MemBase) issues : How can I see if the linear address is wrong?
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## 9.7. How can I see if the linear address is wrong?

Simple: nothing works, or your machine locks solid, or it crashes, or a zillion of other things.

However, sometimes it is not always as obvious. Sometimes nothing bad happens: you just get a black screen, or a screen with rubbish on it, but nothing is drawn on it. Sometimes you get a core dump when the first application starts.

If acceleration is enabled in those cases, you will almost always see multiple "WAIT_ACL: timeout" messages in the server output. That is because the accelerator registers are also mapped in the linear memory, and if linear memory doesn't work, then also the accelerator doesn't work.

NOTE however that a WAIT_ACL message doesn't necessarily mean the linear memory address is bad. There are a number of other reasons for this message as well. But if you never saw these messages at 8bpp banked, then there's a good chance you have a linear memory problem ("banked" is the opposite of "linear", and is the default mode when "option linear" is not in the XF86Config file).

Information for Tseng Chipset Users : linear memory base address (MemBase) issues : How can I see if the linear address is wrong?
Previous: Some boards simply cannot work in linear mode
Next: Mode issues