Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756610Ab3H3MnN (ORCPT ); Fri, 30 Aug 2013 08:43:13 -0400 Received: from mga11.intel.com ([192.55.52.93]:38541 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755785Ab3H3MnJ (ORCPT ); Fri, 30 Aug 2013 08:43:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,990,1367996400"; d="scan'208";a="394507790" Date: Fri, 30 Aug 2013 15:43:05 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Alex Williamson Cc: intel-gfx@lists.freedesktop.org, airlied@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] i915: Update VGA arbiter support for newer devices Message-ID: <20130830124305.GI11428@intel.com> References: <20130828153700.10255.67664.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20130828153700.10255.67664.stgit@bling.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4330 Lines: 116 On Wed, Aug 28, 2013 at 09:39:08AM -0600, Alex Williamson wrote: > This is intended to add VGA arbiter support for Intel HD graphics on > Core processors. The old GMCH registers no longer exist, so even > though it appears that i915 participates in VGA arbitration, it doesn't > work. On Intel HD graphics we already attempt to disable VGA regions > of the device. This makes registering as a VGA client unnecessary since > we don't intend to operate differently depending on how many VGA devices > are present. We can disable VGA memory regions by clearing the memory > enable bit in the VGA MSR. That only leaves VGA IO, which we update > the VGA arbiter to know that we don't participate in VGA memory > arbitration. We also add a hook on unload to re-enable memory and > reinstate VGA memory arbitration. > > Signed-off-by: Alex Williamson Looking good. Reviewed-by: Ville Syrj?l? > --- > > v3: Use explicit LEGACY_IO | LEGACY_MEM when restoring rather than > LEGACY_MASK, per Ville's comments. > > v2: I915_READ/WRITE accessors don't work in i915_disable_vga, use inb/outb > directly. Also, on the driver unbind VGA enable path, acquire legacy > IO to re-enable VGA memory. Correct comment. > > As with v1, this depends on "vgaarb: Fixes for partial VGA opt-out". With > all patches I'm able to assign a discrete PEG VGA device to a guest and > execute the VBIOS w/o interference from IGD or corruption of the IGD > framebuffer. > > drivers/gpu/drm/i915/i915_dma.c | 9 ++++++--- > drivers/gpu/drm/i915/intel_display.c | 25 +++++++++++++++++++++++++ > 2 files changed, 31 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c > index f466980..d9cf216 100644 > --- a/drivers/gpu/drm/i915/i915_dma.c > +++ b/drivers/gpu/drm/i915/i915_dma.c > @@ -1287,9 +1287,12 @@ static int i915_load_modeset_init(struct drm_device *dev) > * then we do not take part in VGA arbitration and the > * vga_client_register() fails with -ENODEV. > */ > - ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode); > - if (ret && ret != -ENODEV) > - goto out; > + if (!HAS_PCH_SPLIT(dev)) { > + ret = vga_client_register(dev->pdev, dev, NULL, > + i915_vga_set_decode); > + if (ret && ret != -ENODEV) > + goto out; > + } > > intel_register_dsm_handler(); > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 5fb3058..2807760 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -9519,6 +9519,15 @@ static void i915_disable_vga(struct drm_device *dev) > outb(SR01, VGA_SR_INDEX); > sr1 = inb(VGA_SR_DATA); > outb(sr1 | 1<<5, VGA_SR_DATA); > + > + /* Disable VGA memory on Intel HD */ > + if (HAS_PCH_SPLIT(dev)) { > + outb(inb(VGA_MSR_READ) & ~VGA_MSR_MEM_EN, VGA_MSR_WRITE); > + vga_set_legacy_decoding(dev->pdev, VGA_RSRC_LEGACY_IO | > + VGA_RSRC_NORMAL_IO | > + VGA_RSRC_NORMAL_MEM); > + } > + > vga_put(dev->pdev, VGA_RSRC_LEGACY_IO); > udelay(300); > > @@ -9526,6 +9535,20 @@ static void i915_disable_vga(struct drm_device *dev) > POSTING_READ(vga_reg); > } > > +static void i915_enable_vga(struct drm_device *dev) > +{ > + /* Enable VGA memory on Intel HD */ > + if (HAS_PCH_SPLIT(dev)) { > + vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO); > + outb(inb(VGA_MSR_READ) | VGA_MSR_MEM_EN, VGA_MSR_WRITE); > + vga_set_legacy_decoding(dev->pdev, VGA_RSRC_LEGACY_IO | > + VGA_RSRC_LEGACY_MEM | > + VGA_RSRC_NORMAL_IO | > + VGA_RSRC_NORMAL_MEM); > + vga_put(dev->pdev, VGA_RSRC_LEGACY_IO); > + } > +} > + > void intel_modeset_init_hw(struct drm_device *dev) > { > intel_init_power_well(dev); > @@ -9983,6 +10006,8 @@ void intel_modeset_cleanup(struct drm_device *dev) > > intel_disable_fbc(dev); > > + i915_enable_vga(dev); > + > intel_disable_gt_powersave(dev); > > ironlake_teardown_rc6(dev); -- Ville Syrj?l? Intel OTC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/