[alsa-devel] hda: Bug - (timing?) problem causes DP monitor to not get activated
Hi,
I'm having a bug here, where the loaded hda module causes some (timing?) problem resulting in a monitor connected to the DP not to get active. I can reproduce this on a Lenovo X201 and T410 (Ironlake) sitting on a docking station, which has a monitor (Dell U2410) connected to a DP.
Steps to reproduce: 1. boot with the laptop at the docking station and the monitor plugged in 2. start the X-Server ... output on LVDS and DP is okay 3. disable the DP: xrandr --output LVDS1 --preferred --output DP1 --off ... output on LVDS - okay 4. switch to DP: xrandr --output LVDS1 --off --output DP1 --preferred ... DP _usually_ doesn't gets active, it turn off into suspend state
Why I think that it is related to the hda module? If I boot a kernel without the hda module step 4 always works. When having the hda module loaded I need some luck and some iterations of step 3 and 4 to activate the monitor at the DP.
I verified that the problem exists in kernel v3.13.1 and v3.14-rc4.
The logs I have attached have been created on the T410 with kernel v3.14-rc4. The first alsa-info....txt has been created right after booting, the second one after step 4 failed. The kernel has been build with all alsa debug options I could find, the config is attached as well, and the kernel has been booted with drm.debug=0xe - this might be to much, but it shows pretty clear when the outputs have been switched.
I hope that anyone can read something usefull - something that went wrong - out of the log files. My unexercised eye can't spot anything obvious.
If more logs are necessary, I'll send them.
Cheers, Daniel Martin
At Fri, 28 Feb 2014 11:47:27 +0100, Daniel Martin wrote:
Hi,
I'm having a bug here, where the loaded hda module causes some (timing?) problem resulting in a monitor connected to the DP not to get active. I can reproduce this on a Lenovo X201 and T410 (Ironlake) sitting on a docking station, which has a monitor (Dell U2410) connected to a DP.
Steps to reproduce:
- boot with the laptop at the docking station and the monitor plugged in
- start the X-Server ... output on LVDS and DP is okay
- disable the DP: xrandr --output LVDS1 --preferred --output DP1 --off ... output on LVDS - okay
- switch to DP: xrandr --output LVDS1 --off --output DP1 --preferred ... DP _usually_ doesn't gets active, it turn off into suspend state
Why I think that it is related to the hda module? If I boot a kernel without the hda module step 4 always works. When having the hda module loaded I need some luck and some iterations of step 3 and 4 to activate the monitor at the DP.
I verified that the problem exists in kernel v3.13.1 and v3.14-rc4.
The logs I have attached have been created on the T410 with kernel v3.14-rc4. The first alsa-info....txt has been created right after booting, the second one after step 4 failed. The kernel has been build with all alsa debug options I could find, the config is attached as well, and the kernel has been booted with drm.debug=0xe - this might be to much, but it shows pretty clear when the outputs have been switched.
I hope that anyone can read something usefull - something that went wrong - out of the log files. My unexercised eye can't spot anything obvious.
If more logs are necessary, I'll send them.
Could you rather post it to intel-gfx ML? (Please keep me in Cc.)
For IronLake, i915_request_power_well() must be irrelevant, thus it can't be the HD-audio's runtime PM refcount. There is no other direct communication with the graphics device, but only via HD-audio's controller and codec; i.e. it's communicated via a normal hardware channel. If anything in the graphic output doesn't work in that situation, the likely culprit is rather in the graphics side.
thanks,
Takashi
participants (2)
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Daniel Martin -
Takashi Iwai