Bug 16536

Summary: [G33] X shows no video and displays "underrun on pipe A" error
Product: xorg Reporter: Jonathan Medefind <jmedefind>
Component: Driver/intelAssignee: Jesse Barnes <jbarnes>
Status: RESOLVED DUPLICATE QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium Keywords: NEEDINFO
Version: git   
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log
none
xorg.conf
none
dmesg none

Description Jonathan Medefind 2008-06-26 19:29:09 UTC
Whenever I try to start X I get no video input on the monitor and X.log shows an error stating "underrun on pipe A"
Comment 1 Jonathan Medefind 2008-06-26 19:29:44 UTC
Created attachment 17406 [details]
Xorg.0.log
Comment 2 Jonathan Medefind 2008-06-26 19:31:06 UTC
Created attachment 17407 [details]
xorg.conf
Comment 3 Jonathan Medefind 2008-06-26 19:31:21 UTC
Created attachment 17408 [details]
dmesg
Comment 4 Gordon Jin 2008-06-27 00:09:33 UTC
seems similar to bug#16169.
Comment 5 Jesse Barnes 2008-07-01 18:37:38 UTC
Can you try this?  I'm pretty sure that reprogramming DSPARB is a bad idea on some machines, maybe including yours.

diff --git a/src/i830_driver.c b/src/i830_driver.c
index dff7d51..2e8f5eb 100644
--- a/src/i830_driver.c
+++ b/src/i830_driver.c
@@ -3408,7 +3408,7 @@ I830EnterVT(int scrnIndex, int flags)
    /* Set the DSPARB register.  This disables the outputs, which is about to
     * happen (likely) in xf86SetDesiredModes anyway.
     */
-   i830_set_dsparb(pScrn);
+//   i830_set_dsparb(pScrn);

    /* Tell the BIOS that we're in control of mode setting now. */
    i830_init_bios_control(pScrn);
Comment 6 Jesse Barnes 2008-07-08 10:15:37 UTC

*** This bug has been marked as a duplicate of bug 16169 ***

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