On Fri, May 04, 2012 at 11:29:56AM +0200, Daniel Vetter wrote: > Chris Wilson dug out a hw erratum saying that there's noise on the > interrupt line on i945G chips. We also have a bug report from a i945GM > chip with an sdvo hotplug interrupt storm (and no apparent cause). > > Play it safe and disable sdvo hotplug on all i945 variants. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=38442 > Reported-and-tested-by: Dominik K?ppl <dominik at devwork.org> > Cc: Chris Wilson <chris at chris-wilson.co.uk> > Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch> I've just realized that this is a regression that has been introduced in 3.1, when we've enabled sdvo hotplug support with commit cc68c81aed7d892deaf12d720d5455208e94cd0a Author: Simon Farnsworth <simon.farnsworth at onelan.co.uk> Date: Wed Sep 21 17:13:30 2011 +0100 drm/i915: Enable SDVO hotplug interrupts for HDMI and DVI Cc: stable at kernel.org -Daniel > --- > drivers/gpu/drm/i915/intel_sdvo.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c > index c330efd..bf6be6c 100644 > --- a/drivers/gpu/drm/i915/intel_sdvo.c > +++ b/drivers/gpu/drm/i915/intel_sdvo.c > @@ -1232,8 +1232,14 @@ static bool intel_sdvo_get_capabilities(struct intel_sdvo *intel_sdvo, struct in > > static int intel_sdvo_supports_hotplug(struct intel_sdvo *intel_sdvo) > { > + struct drm_device *dev = intel_sdvo->base.base.dev; > u8 response[2]; > > + /* HW Erratum: SDVO Hotplug is broken on all i945G chips, there's noise > + * on the line. */ > + if (IS_I945G(dev) || IS_I945GM(dev)) > + return false; > + > return intel_sdvo_get_value(intel_sdvo, SDVO_CMD_GET_HOT_PLUG_SUPPORT, > &response, 2) && response[0]; > } > -- > 1.7.10 > -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
