From ebff5fa9d545574324095d9c6a3cb80c9157abc5 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Fri, 11 Oct 2013 15:12:04 +1000 Subject: [PATCH] Revert "i915: Update VGA arbiter support for newer devices" MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This reverts commit 81b5c7bc8de3e6f63419139c2fc91bf81dea8a7d. Adding drm/i915 into the vga arbiter chain means that X (in a piece of well-meant paranoia) will do a get/put on the vga decoding around _every_ accel call down into the ddx. Which results in some nice performance disasters [1]. This really breaks userspace, by disabling DRI for everyone, and stops OpenGL from working, this isn't limited to just the i915 but both the integrated and discrete GPUs on multi-gpu systems, in other words this causes untold worlds of pain, Ville tried to come up with a Great Hack to fiddle the required VGA I/O ops behind everyone's back using stop_machine, but that didn't really work out [2]. Given that we're fairly late in the -rc stage for such games let's just revert this all. One thing we might want to keep is to delay the disabling of the vga decoding until the fbdev emulation and the fbcon screen is set up. If we kill vga mem decoding beforehand fbcon can end up with a white square in the top-left corner it tried to save from the vga memory for a seamless transition. And we have bug reports on older platforms which seem to match these symptoms. But again that's something to play around with in -next. References: [1] http://lists.x.org/archives/xorg-devel/2013-September/037763.html References: [2] http://www.spinics.net/lists/intel-gfx/msg34062.html Cc: Alex Williamson Cc: Ville Syrjälä Cc: Chris Wilson Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/i915_dma.c | 9 +++------ drivers/gpu/drm/i915/intel_display.c | 25 ------------------------- include/linux/vgaarb.h | 7 ------- 3 files changed, 3 insertions(+), 38 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 52f5ad8037cc..d5c784d48671 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1290,12 +1290,9 @@ 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. */ - if (!HAS_PCH_SPLIT(dev)) { - ret = vga_client_register(dev->pdev, dev, NULL, - i915_vga_set_decode); - if (ret && ret != -ENODEV) - goto out; - } + 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 aaea3ec811ed..581fb4b2f766 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10038,15 +10038,6 @@ 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); @@ -10054,20 +10045,6 @@ 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); @@ -10559,8 +10536,6 @@ 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); diff --git a/include/linux/vgaarb.h b/include/linux/vgaarb.h index 80cf8173a65b..2c02f3a8d2ba 100644 --- a/include/linux/vgaarb.h +++ b/include/linux/vgaarb.h @@ -65,15 +65,8 @@ struct pci_dev; * out of the arbitration process (and can be safe to take * interrupts at any time. */ -#if defined(CONFIG_VGA_ARB) extern void vga_set_legacy_decoding(struct pci_dev *pdev, unsigned int decodes); -#else -static inline void vga_set_legacy_decoding(struct pci_dev *pdev, - unsigned int decodes) -{ -} -#endif /** * vga_get - acquire & locks VGA resources -- 2.20.1