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drm/i915: i8xx interrupt handler
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gen2 hardware has some significant differences from the other interrupt
routines that were glossed over and then forgotten about in the
transition to KMS. Such as

- 16bit IIR
- PendingFlip status bit

This patch reintroduces a handler specifically for gen2 for the purpose
of handling pageflips correctly, simplifying code in the process.

v2: Also fixup ring get/put irq to only access 16bit registers (Daniel)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=24202
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41793
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: use posting_read16 in intel_ringbuffer.c and kill _driver
from the function names.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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Chris Wilson authored and Daniel Vetter committed May 3, 2012
1 parent 1869b62 commit c2798b1
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Showing 2 changed files with 206 additions and 8 deletions.
161 changes: 157 additions & 4 deletions drivers/gpu/drm/i915/i915_irq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2446,6 +2446,152 @@ static void i915_driver_irq_uninstall(struct drm_device * dev)
I915_WRITE(IIR, I915_READ(IIR));
}

static void i8xx_irq_preinstall(struct drm_device * dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
int pipe;

atomic_set(&dev_priv->irq_received, 0);

for_each_pipe(pipe)
I915_WRITE(PIPESTAT(pipe), 0);
I915_WRITE16(IMR, 0xffff);
I915_WRITE16(IER, 0x0);
POSTING_READ16(IER);
}

static int i8xx_irq_postinstall(struct drm_device *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;

dev_priv->pipestat[0] = 0;
dev_priv->pipestat[1] = 0;

I915_WRITE16(EMR,
~(I915_ERROR_PAGE_TABLE | I915_ERROR_MEMORY_REFRESH));

/* Unmask the interrupts that we always want on. */
dev_priv->irq_mask =
~(I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT |
I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
I915_WRITE16(IMR, dev_priv->irq_mask);

I915_WRITE16(IER,
I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT |
I915_USER_INTERRUPT);
POSTING_READ16(IER);

return 0;
}

static irqreturn_t i8xx_irq_handler(DRM_IRQ_ARGS)
{
struct drm_device *dev = (struct drm_device *) arg;
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
struct drm_i915_master_private *master_priv;
u16 iir, new_iir;
u32 pipe_stats[2];
unsigned long irqflags;
int irq_received;
int pipe;
u16 flip_mask =
I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT |
I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;

atomic_inc(&dev_priv->irq_received);

iir = I915_READ16(IIR);
if (iir == 0)
return IRQ_NONE;

while (iir & ~flip_mask) {
/* Can't rely on pipestat interrupt bit in iir as it might
* have been cleared after the pipestat interrupt was received.
* It doesn't set the bit in iir again, but it still produces
* interrupts (for non-MSI).
*/
spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
i915_handle_error(dev, false);

for_each_pipe(pipe) {
int reg = PIPESTAT(pipe);
pipe_stats[pipe] = I915_READ(reg);

/*
* Clear the PIPE*STAT regs before the IIR
*/
if (pipe_stats[pipe] & 0x8000ffff) {
if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
DRM_DEBUG_DRIVER("pipe %c underrun\n",
pipe_name(pipe));
I915_WRITE(reg, pipe_stats[pipe]);
irq_received = 1;
}
}
spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);

I915_WRITE16(IIR, iir & ~flip_mask);
new_iir = I915_READ16(IIR); /* Flush posted writes */

if (dev->primary->master) {
master_priv = dev->primary->master->driver_priv;
if (master_priv->sarea_priv)
master_priv->sarea_priv->last_dispatch =
READ_BREADCRUMB(dev_priv);
}

if (iir & I915_USER_INTERRUPT)
notify_ring(dev, &dev_priv->ring[RCS]);

if (pipe_stats[0] & PIPE_VBLANK_INTERRUPT_STATUS &&
drm_handle_vblank(dev, 0)) {
if (iir & I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT) {
intel_prepare_page_flip(dev, 0);
intel_finish_page_flip(dev, 0);
flip_mask &= ~I915_DISPLAY_PLANE_A_FLIP_PENDING_INTERRUPT;
}
}

if (pipe_stats[1] & PIPE_VBLANK_INTERRUPT_STATUS &&
drm_handle_vblank(dev, 1)) {
if (iir & I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT) {
intel_prepare_page_flip(dev, 1);
intel_finish_page_flip(dev, 1);
flip_mask &= ~I915_DISPLAY_PLANE_B_FLIP_PENDING_INTERRUPT;
}
}

iir = new_iir;
}

return IRQ_HANDLED;
}

static void i8xx_irq_uninstall(struct drm_device * dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
int pipe;

dev_priv->vblank_pipe = 0;

for_each_pipe(pipe) {
/* Clear enable bits; then clear status bits */
I915_WRITE(PIPESTAT(pipe), 0);
I915_WRITE(PIPESTAT(pipe), I915_READ(PIPESTAT(pipe)));
}
I915_WRITE16(IMR, 0xffff);
I915_WRITE16(IER, 0x0);
I915_WRITE16(IIR, I915_READ16(IIR));
}

void intel_irq_init(struct drm_device *dev)
{
dev->driver->get_vblank_counter = i915_get_vblank_counter;
Expand Down Expand Up @@ -2485,10 +2631,17 @@ void intel_irq_init(struct drm_device *dev)
dev->driver->enable_vblank = ironlake_enable_vblank;
dev->driver->disable_vblank = ironlake_disable_vblank;
} else {
dev->driver->irq_preinstall = i915_driver_irq_preinstall;
dev->driver->irq_postinstall = i915_driver_irq_postinstall;
dev->driver->irq_uninstall = i915_driver_irq_uninstall;
dev->driver->irq_handler = i915_driver_irq_handler;
if (INTEL_INFO(dev)->gen == 2) {
dev->driver->irq_preinstall = i8xx_irq_preinstall;
dev->driver->irq_postinstall = i8xx_irq_postinstall;
dev->driver->irq_handler = i8xx_irq_handler;
dev->driver->irq_uninstall = i8xx_irq_uninstall;
} else {
dev->driver->irq_preinstall = i915_driver_irq_preinstall;
dev->driver->irq_postinstall = i915_driver_irq_postinstall;
dev->driver->irq_uninstall = i915_driver_irq_uninstall;
dev->driver->irq_handler = i915_driver_irq_handler;
}
dev->driver->enable_vblank = i915_enable_vblank;
dev->driver->disable_vblank = i915_disable_vblank;
}
Expand Down
53 changes: 49 additions & 4 deletions drivers/gpu/drm/i915/intel_ringbuffer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -678,6 +678,41 @@ i9xx_ring_put_irq(struct intel_ring_buffer *ring)
spin_unlock(&ring->irq_lock);
}

static bool
i8xx_ring_get_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;

if (!dev->irq_enabled)
return false;

spin_lock(&ring->irq_lock);
if (ring->irq_refcount++ == 0) {
dev_priv->irq_mask &= ~ring->irq_enable_mask;
I915_WRITE16(IMR, dev_priv->irq_mask);
POSTING_READ16(IMR);
}
spin_unlock(&ring->irq_lock);

return true;
}

static void
i8xx_ring_put_irq(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
drm_i915_private_t *dev_priv = dev->dev_private;

spin_lock(&ring->irq_lock);
if (--ring->irq_refcount == 0) {
dev_priv->irq_mask |= ring->irq_enable_mask;
I915_WRITE16(IMR, dev_priv->irq_mask);
POSTING_READ16(IMR);
}
spin_unlock(&ring->irq_lock);
}

void intel_ring_setup_status_page(struct intel_ring_buffer *ring)
{
struct drm_device *dev = ring->dev;
Expand Down Expand Up @@ -1310,8 +1345,13 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
else
ring->flush = gen4_render_ring_flush;
ring->get_seqno = ring_get_seqno;
ring->irq_get = i9xx_ring_get_irq;
ring->irq_put = i9xx_ring_put_irq;
if (IS_GEN2(dev)) {
ring->irq_get = i8xx_ring_get_irq;
ring->irq_put = i8xx_ring_put_irq;
} else {
ring->irq_get = i9xx_ring_get_irq;
ring->irq_put = i9xx_ring_put_irq;
}
ring->irq_enable_mask = I915_USER_INTERRUPT;
}
ring->write_tail = ring_write_tail;
Expand Down Expand Up @@ -1358,8 +1398,13 @@ int intel_render_ring_init_dri(struct drm_device *dev, u64 start, u32 size)
else
ring->flush = gen4_render_ring_flush;
ring->get_seqno = ring_get_seqno;
ring->irq_get = i9xx_ring_get_irq;
ring->irq_put = i9xx_ring_put_irq;
if (IS_GEN2(dev)) {
ring->irq_get = i8xx_ring_get_irq;
ring->irq_put = i8xx_ring_put_irq;
} else {
ring->irq_get = i9xx_ring_get_irq;
ring->irq_put = i9xx_ring_put_irq;
}
ring->irq_enable_mask = I915_USER_INTERRUPT;
ring->write_tail = ring_write_tail;
if (INTEL_INFO(dev)->gen >= 4)
Expand Down

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