Bug 92311

Summary: vga corruption on SM 750 GPU
Product: Drivers Reporter: Dave Airlie (airlied)
Component: Video(Other)Assignee: drivers_video-other
Status: NEEDINFO ---    
Severity: normal CC: alan
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 3.19 Subsystem:
Regression: No Bisected commit-id:
Attachments: image showing corruption

Description Dave Airlie 2015-01-29 23:41:54 UTC
Created attachment 165221 [details]
image showing corruption

Due to a hw bug in ths GPU 64-bit writes to the VGA seem to corrupt things.

Originally reported in RH bugzilla against RHEL6 vs RHEL5 behaviour on 32 vs 64-bit systems.

Steps to Reproduce:
1.modify the runlevel to 3, to use vga mode.
2.use vim to edit some file, and scroll up
3.the vga display messy code
Comment 1 Alan 2015-02-10 15:37:26 UTC
Is it the 64bit wide writes or reads that do the damage.

Is the framebuffer memory marked write combining at the bridge ?