[Patch] The resolution of Display Port for intel cards is limited
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
Medium
|
Herton R. Krzesinski | ||
Oneiric |
Invalid
|
Medium
|
Unassigned | ||
Precise |
Fix Released
|
Medium
|
Herton R. Krzesinski |
Bug Description
SRU Justification
Impact
Unable to achieve some resolutions through display port because of
driver miscalculation, or sub-optimal number of links x data rate
chosen.
Fix
upstream commit cd9dde44f475013
Testcase
Try attach something to display port using a resolution which should be
supported by the hardware but isn't by the driver, or enable relevant
debug and watch dmesg for sub-optimal links x data rate chosen (eg.:
http://
=======
Speaking with the intel driver developers they told me there was a mistake on how the needed bandwidth was calculated resulting in higher resolutions not being accepted because the driver though DisplayPort did not have enough bandwidth for it.
Commit cd9dde44f475013
ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: linux-image (not installed)
ProcVersionSign
Uname: Linux 3.0.0-13-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC665 Analog [ALC665 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
CRDA: Error: [Errno 2] El fitxer o directori no existeix
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xf1c00000 irq 52'
Mixer name : 'Intel CougarPoint HDMI'
Components : 'HDA:10ec0665,
Controls : 27
Simple ctrls : 13
Date: Sat Dec 3 15:11:01 2011
HibernationDevice: RESUME=
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: Dell Inc. Dell System XPS L502X
ProcKernelCmdLine: BOOT_IMAGE=
RelatedPackageV
linux-
linux-
linux-firmware 1.60
SourcePackage: linux
StagingDrivers: mei
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/20/2011
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A07
dmi.board.name: 0YR8NN
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.
dmi.modalias: dmi:bvnDellInc.
dmi.product.name: Dell System XPS L502X
dmi.sys.vendor: Dell Inc.
Related branches
Changed in linux (Ubuntu): | |
status: | New → Confirmed |
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
status: | Confirmed → Triaged |
Changed in linux (Ubuntu Oneiric): | |
status: | Incomplete → Fix Committed |
Changed in linux (Ubuntu Oneiric): | |
status: | Confirmed → Invalid |
@Albert: please check the patch, is the backport the same you have done for a 3.0.0 kernel? Also does the SRU description matches your issue, what hardware/resolution are you using and is giving problems?
If everything is ok I'll submit this to the kernel-team mailing list for inclusion.