<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [Regression BDW] backlight flickering/display artifacting on Broadwell integrated graphics with 4.12-rc1"
href="https://bugs.freedesktop.org/show_bug.cgi?id=101111">101111</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[Regression BDW] backlight flickering/display artifacting on Broadwell integrated graphics with 4.12-rc1
</td>
</tr>
<tr>
<th>Product</th>
<td>DRI
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>x86-64 (AMD64)
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>critical
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>DRM/Intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>nicholas.stommel@gmail.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>intel-gfx-bugs@lists.freedesktop.org
</td>
</tr></table>
<p>
<div>
<pre>As of 4.12-rc1, the following regression happens:
On a laptop with integrated Broadwell 5500U graphics, I am experiencing a
slight but noticeable and extremely annoying backlight flickering. This is
especially apparent when the screen brightness is adjusted high on dark grey
backgrounds where there is a noticeable sort of constant flickering/variation
in brightness of the background sometimes striated with thin lines but usually
just flickering slightly lighter or darker. Of course, this occurs at all
brightness levels, but is more obvious there. This problem has only been
present as of the release of 4.12-rc1, and is also present on drm-tip and
drm-intel-nightly. It seems related to the updates in the i915 Intel integrated
graphics module. It's problematic enough to be a fairly major annoyance on the
5500U Broadwell SoC.
The following is my system configuration. I can confirm that this problem
occurs even with the latest intel firmware/drivers in Ubuntu 17.04 as well as
on my primary system running Ubuntu 16.04.2 LTS, and that it does not happen on
4.11.x or previous kernels.
uname -a
Linux delphi 4.12.0-041200rc1-generic #201705131731 SMP Sat May 13 21:32:36 UTC
2017 x86_64 x86_64 x86_64 GNU/Linux
sudo lshw -short
H/W path Device Class Description
====================================================
system HP Spectre x360 Convertible (N5R94UA)
/0 bus 802D
/0/0 memory 64KiB BIOS
/0/10 memory 32KiB L1 cache
/0/11 memory 32KiB L1 cache
/0/12 memory 256KiB L2 cache
/0/13 memory 4MiB L3 cache
/0/14 processor Intel(R) Core(TM) i7-5500U CPU @
2.40GH
/0/16 memory 8GiB System Memory
/0/16/0 memory 4GiB Row of chips Synchronous 1600 MHz
/0/16/1 memory 4GiB Row of chips Synchronous 1600 MHz
/0/100 bridge Broadwell-U Host Bridge -OPI
/0/100/2 display Broadwell-U Integrated Graphics
/0/100/3 multimedia Broadwell-U Audio Controller
/0/100/14 bus Wildcat Point-LP USB xHCI Controller
/0/100/14/0 usb1 bus xHCI Host Controller
/0/100/14/0/1 input USB Receiver
/0/100/14/0/3 multimedia HP Truevision Full HD
/0/100/14/0/4 input Touchscreen
/0/100/14/0/5 input ITE Device(8350)
/0/100/14/0/7 communication Bluetooth wireless interface
/0/100/14/1 usb2 bus xHCI Host Controller
/0/100/16 communication Wildcat Point-LP MEI Controller #1
/0/100/1c bridge Wildcat Point-LP PCI Express Root Port
/0/100/1c/0 generic RTS5227 PCI Express Card Reader
/0/100/1c.2 bridge Wildcat Point-LP PCI Express Root Port
/0/100/1c.2/0 wlo1 network Wireless 7265
/0/100/1f bridge Wildcat Point-LP LPC Controller
/0/100/1f.2 storage Wildcat Point-LP SATA Controller [AHCI
/0/100/1f.3 bus Wildcat Point-LP SMBus Controller
/0/1 scsi0 storage
/0/1/0.0.0 /dev/sda disk 512GB SAMSUNG MZNTE512
/0/1/0.0.0/1 /dev/sda1 volume 449MiB Windows NTFS volume
/0/1/0.0.0/2 /dev/sda2 volume 99MiB Windows FAT volume
/0/1/0.0.0/3 /dev/sda3 volume 15MiB reserved partition
/0/1/0.0.0/4 /dev/sda4 volume 15EiB Windows FAT volume
/0/1/0.0.0/5 /dev/sda5 volume 838MiB Windows NTFS volume
/0/1/0.0.0/6 /dev/sda6 volume 146GiB Windows NTFS volume
/0/1/0.0.0/7 /dev/sda7 volume 89GiB EXT4 volume
/0/1/0.0.0/8 /dev/sda8 volume 8099MiB Linux swap volume
/1 power PK03056XL</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
<li>You are the assignee for the bug.</li>
<li>You are the QA Contact for the bug.</li>
</ul>
</body>
</html>