MacBook Pro 2015 flickers horribly
 

My MacBook Pro's screen has had flickering issues since, well, a couple of -current updates ago. By "flickering" I mean the screen going dark for very small units of time. It happens when I load ads in Chromium, when I type in the Chromium address bar, and especially when slackpkg is downloading stuff.

It seems to have a correlation with network activity. However, it does not happen in OS X, so we can eliminate the possibility of a hardware issue.

I've tried using an xorg.conf.d file to set the acceleration method to UXA and to SNA. Neither seems to make a difference.

I've found this bug report, which looks to be relevant. I haven't had a chance to try any of the patches in it yet though.

https://bugs.freedesktop.org/show_bug.cgi?id=91393

We've been discussing intel driver issues over here, and had some success rebuilding the intel driver using a different revision. I was seeing something similar on my XPS but it's gone away on the newer driver. Your mileage may vary of course..

I had some flickering problems at random times with an Acer laptop.

The fix turned out to be adding this line to the boot stanza in elilo.conf:

@rkelsen I tried that module option (in modprobe.conf) and it didn't make a difference.

Could it be hardware failure? That's the worse flicker to encounter ime

it was a nvidia 6800gt from beginning to end

does it happen in the terminal?

I would still see the flicker if I switched to a virtual console when it was happening in X. I didn't have a chance to test from runlevel 3 (there were no -current updates to download since the 6th), but I will when I pull the update that -current got today.

I find it very unlikely that it would be hardware failure, as it started happening after a slackpkg update and it does not happen in OS X. I am starting to wonder if it what broke it might have been the 4.4.6 kernel and/or its wifi driver though. I've seen google hits about broadcom drivers causing similar symptoms on very similar machines.

Linux-4.4.7 was released today. If Pat doesn't put out an update right away, it might be worth compiling it yourself to see if there's a fix...

The problem has randomly gone away. I have no idea why it's no longer happening, but I'm not complaining.

Did you grab the latest -current upgrade?

It went away before I did that.

The problem's started up again.

I haven't checked my lspci or lsmod output yet, but I'll be looking to the possibility that the b432 kernel module might be the problem.

I *did* see references to this happening on OS X, and if it happens to me on OS X I'll take it in. For me, though, it hasn't happened on OS X yet.

Looks like it might be caused by the brcmfmac kernel module. I'm going to go out and buy a wifi dongle.