From 81b5c7bc8de3e6f63419139c2fc91bf81dea8a7d Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Wed, 28 Aug 2013 09:39:08 -0600 Subject: [PATCH] i915: Update VGA arbiter support for newer devices MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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. 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. Signed-off-by: Alex Williamson Reviewed-by: Ville Syrjälä [danvet: Add patch changelog. Also squash in a fixup to have a dummy static inline for vga_set_legacy_decoding for CONFIG_VGA_ARB=n as reported by the 0-day kernel build bot.] Signed-off-by: Daniel Vetter fixup 2 --- drivers/gpu/drm/i915/i915_dma.c | 9 ++++++--- drivers/gpu/drm/i915/intel_display.c | 25 +++++++++++++++++++++++++ include/linux/vgaarb.h | 7 +++++++ 3 files changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index fdaa0915ce56..3de60503378e 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1290,9 +1290,12 @@ 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 a1e502b07266..73dec62f871f 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10041,6 +10041,15 @@ 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); @@ -10048,6 +10057,20 @@ 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); @@ -10539,6 +10562,8 @@ 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); diff --git a/include/linux/vgaarb.h b/include/linux/vgaarb.h index 2c02f3a8d2ba..80cf8173a65b 100644 --- a/include/linux/vgaarb.h +++ b/include/linux/vgaarb.h @@ -65,8 +65,15 @@ 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