From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751387Ab1ITQgg (ORCPT ); Tue, 20 Sep 2011 12:36:36 -0400 Received: from home.keithp.com ([63.227.221.253]:36612 "EHLO keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772Ab1ITQgf (ORCPT ); Tue, 20 Sep 2011 12:36:35 -0400 From: Keith Packard To: Chris Wilson , Dave Airlie Cc: intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/i915: Enable digital port hotplug on PCH systems In-Reply-To: References: <1316533641-13478-1-git-send-email-keithp@keithp.com> User-Agent: Notmuch/0.6.1-66-ga900dda (http://notmuchmail.org) Emacs/23.3.1 (i486-pc-linux-gnu) Date: Tue, 20 Sep 2011 09:36:31 -0700 Message-ID: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Transfer-Encoding: quoted-printable On Tue, 20 Sep 2011 17:24:21 +0100, Chris Wilson = wrote: > On Tue, 20 Sep 2011 08:47:21 -0700, Keith Packard wro= te: > > We were relying on the BIOS to set these bits, which doesn't always > > happen. >=20 > Do we need to clear IRQ bits on uninstall, for example to prevent > "Interrupt 19: no one cared!" or is that due to a different cause? Probably a good plan, but of course that's separate from turning on the hotplug hardware in the PCH. Something like: diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_ir= q.c index c22823b..adeab2a 100644 =2D-- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2044,6 +2044,10 @@ static void ironlake_irq_uninstall(struct drm_device= *dev) I915_WRITE(GTIMR, 0xffffffff); I915_WRITE(GTIER, 0x0); I915_WRITE(GTIIR, I915_READ(GTIIR)); + + I915_WRITE(SDEIMR, 0xffffffff); + I915_WRITE(SDEIER, 0x0); + I915_WRITE(SDEIIR, I915_READ(SDEIIR)); } =20 static void i915_driver_irq_uninstall(struct drm_device * dev) > More of a general question really. The patch itself looks good and > matches against the spec afaics. I was amused to learn that the BIOS on my machine actually turns on the hotplug hardware for no good reason, so things 'worked' without this code on many machines. I wonder how many DP/DVI/HDMI machines aren't actually doing hotplug today... =2D-=20 keith.packard@intel.com --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iD8DBQFOeMEPQp8BWwlsTdMRArqBAJ9crXczcwb2Zl5rJAQ/8110izZGHACglXyq DKRpdqQGKWX0y1xvo++LcHs= =Z4iz -----END PGP SIGNATURE----- --=-=-=--