From: Daniel Vetter Date: Fri, 4 May 2012 09:29:56 +0000 (+0200) Subject: drm/i915: disable sdvo hotplug on i945g/gm X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=768b107e4b3be0acf6f58e914afe4f337c00932b;p=deliverable%2Flinux.git drm/i915: disable sdvo hotplug on i945g/gm 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. Note 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 Date: Wed Sep 21 17:13:30 2011 +0100 drm/i915: Enable SDVO hotplug interrupts for HDMI and DVI Cc: stable@kernel.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=38442 Reported-and-tested-by: Dominik Köppl Reviewed-by: Chris Wilson Signed-Off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c index 232d77d07d8b..ae5e748f39bb 100644 --- a/drivers/gpu/drm/i915/intel_sdvo.c +++ b/drivers/gpu/drm/i915/intel_sdvo.c @@ -1220,8 +1220,14 @@ 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]; }