Bug 79015

Created attachment 99527 [details]
XOrg Log using current git intel driver

Created attachment 99528 [details]
XOrg Log using previous dev release intel driver

Created attachment 99529 [details]
XOrg Conf (with Monitor config)

Okay - so first thing's first.  My initial feedback was wrong.  Apparently Arch has switched to dumping all XOrg log output into systemd so I was looking at an old log file.  Using journalctl I have pulled the log entries that are generated for the XOrg intel driver using both the previous dev release driver and the current git version.  In the previous dev release I get this item logged:

Output eDP1 using monitor section Monitor0

Whereas with the git version I get this instead:

Output eDP1 has no monitor section

That would appear to be the root cause.  Any idea why my Monitor section is being ignored in the current version of the driver?  Do I need to add something to my xorg.conf to force it to work?  Or is this no longer supported?

No, it should still be supported. I guess I broke something preparing things for MST support.

I would say the erroneous commit is 

commit add84cd8a8dc6d285912d0ea3a3a3e7faa9e0942
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri May 2 13:21:02 2014 +0100

    sna: Perform dynamic connector discovery
    
    One of the side-effects of MST is that we need to support dynamic
    attachment and removal of displays as the branch hierachy changes.

that would be useful to confirm.

Okay so I'm reviewed the xorg docs and determined that adding the following line to my device section might work around the issue:

Option      "Monitor-eDP1"              "Monitor0"

Sure enough, that did the trick.  So while my immediate issue has been resolved I guess the question is:  Is this actually a bug that needs to be fixed?

Ah,

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index f1cb08d..1132330 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -3023,8 +3023,8 @@ sna_output_add(struct sna *sna, int id, int serial)
        output->name = (char *)(output + 1);
        memcpy(output->name, name, len + 1);
 
-       output->use_screen_monitor = config->num_output;
-       xf86OutputUseScreenMonitor(output, !config->num_output);
+       output->use_screen_monitor = config->num_output != 1;
+       xf86OutputUseScreenMonitor(output, !output->use_screen_monitor);
 
 reset:
        sna_output->id = compat_conn.conn.connector_id;

Nevermind, I see that you've already commented on it.  Well thanks for the feedback.  If you need anything else from me, please do not hesitate to ask!  Again thank you for all of your great work!

Sure, if you could care to test the diff pasted, that would be useful. :)

I had to redo the patch as it's failed to apply.  I presume the position is different as you are probably working on something else in the same file.  Long story short: It appeared to do the trick.

commit 00d9396f6bf0bbbdfca7cdb1cbdbde8f0b2ad59c
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Wed May 21 20:00:56 2014 +0100

    sna: Fix attachment of the default monitor to the first output
    
    Broke during code motion in
    
    commit add84cd8a8dc6d285912d0ea3a3a3e7faa9e0942
    Author: Chris Wilson <chris@chris-wilson.co.uk>
    Date:   Fri May 2 13:21:02 2014 +0100
    
        sna: Perform dynamic connector discovery
    
    Reported-and-tested-by: Jay Little <jaylittle@jaylittle.com>
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79015
    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>