On 11/07/2012 09:36 AM, Takashi Iwai wrote:
At Wed, 7 Nov 2012 09:22:33 +0100, David Henningsson wrote:
On some of the PantherPoint HDMI machines we currently enable, we're seeing trouble with unsol events, i e detecting monitor presence, especially when on battery and after suspend/resume.
BugLink: https://bugs.launchpad.net/bugs/1075882 Tested-by: Cyrus Lien cyrus.lien@canonical.com Signed-off-by: David Henningsson david.henningsson@canonical.com
sound/pci/hda/patch_hdmi.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
So far this is the workaround we have found to be working. Sometimes, it also seems that "cat /proc/asound/cardx/codec#x" can also make the HDMI unsol event trigger, so that the problem fixes itself.
We have not run any battery life tests to see if this causes more power consumption.
Looks safe at least, so I applied to for-next branch to give more testing. If you find a better solution, let me know.
Jesse has now done a battery life test, both for idle machine and S3 machine, and both with HDMI connected and HDMI unconnected.
All differences in power consumption were within error margins. Given that, should we consider sending this patch to stable?