static void skl_power_well_post_enable(struct drm_i915_private *dev_priv,
struct i915_power_well *power_well)
{
struct drm_device *dev = dev_priv->dev;
/*
* After we re-enable the power well, if we touch VGA register 0x3d5
* we'll get unclaimed register interrupts. This stops after we write
* anything to the VGA MSR register. The vgacon module uses this
* register all the time, so if we unbind our driver and, as a
* consequence, bind vgacon, we'll get stuck in an infinite loop at
* console_unlock(). So make here we touch the VGA MSR register, making
* sure vgacon can keep working normally without triggering interrupts
* and error messages.
*/
if (power_well->data == SKL_DISP_PW_2) {
vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
outb(inb(VGA_MSR_READ), VGA_MSR_WRITE);
vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);
gen8_irq_power_well_post_enable(dev_priv,
1 << PIPE_C | 1 << PIPE_B);
}
if (power_well->data == SKL_DISP_PW_1) {
intel_prepare_ddi(dev);
gen8_irq_power_well_post_enable(dev_priv, 1 << PIPE_A);
}
}
/*
* Starting with Haswell, we have a "Power Down Well" that can be turned off
* when not needed anymore. We have 4 registers that can request the power well
* to be enabled, and it will only be disabled if none of the registers is
* requesting it to be enabled.
*/
static void hsw_power_well_post_enable(struct drm_i915_private *dev_priv)
{
struct drm_device *dev = dev_priv->dev;
/*
* After we re-enable the power well, if we touch VGA register 0x3d5
* we'll get unclaimed register interrupts. This stops after we write
* anything to the VGA MSR register. The vgacon module uses this
* register all the time, so if we unbind our driver and, as a
* consequence, bind vgacon, we'll get stuck in an infinite loop at
* console_unlock(). So make here we touch the VGA MSR register, making
* sure vgacon can keep working normally without triggering interrupts
* and error messages.
*/
vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
outb(inb(VGA_MSR_READ), VGA_MSR_WRITE);
vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);
if (IS_BROADWELL(dev) || (INTEL_INFO(dev)->gen >= 9))
gen8_irq_power_well_post_enable(dev_priv);
}
