/*
* Copyright © 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Daniel Vetter <daniel.vetter@ffwll.ch>
*
*/
#include "i915_drv.h"
#include "intel_drv.h"
/**
* DOC: fifo underrun handling
*
* The i915 driver checks for display fifo underruns using the interrupt signals
* provided by the hardware. This is enabled by default and fairly useful to
* debug display issues, especially watermark settings.
*
* If an underrun is detected this is logged into dmesg. To avoid flooding logs
* and occupying the cpu underrun interrupts are disabled after the first
* occurrence until the next modeset on a given pipe.
*
* Note that underrun detection on gmch platforms is a bit more ugly since there
* is no interrupt (despite that the signalling bit is in the PIPESTAT pipe
* interrupt register). Also on some other platforms underrun interrupts are
* shared, which means that if we detect an underrun we need to disable underrun
* reporting on all pipes.
*
* The code also supports underrun detection on the PCH transcoder.
*/
static bool ivb_can_enable_err_int(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_crtc *crtc;
enum pipe pipe;
assert_spin_locked(&dev_priv->irq_lock);
for_each_pipe(dev_priv, pipe) {
crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
if (crtc->cpu_fifo_underrun_disabled)
return false;
}
return true;
}
static bool cpt_can_enable_serr_int(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
enum pipe pipe;
struct intel_crtc *crtc;
assert_spin_locked(&dev_priv->irq_lock);
for_each_pipe(dev_priv, pipe) {
crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
if (crtc->pch_fifo_underrun_disabled)
return false;
}
return true;
}
/**
* i9xx_check_fifo_underruns - check for fifo underruns
* @dev_priv: i915 device instance
*
* This function checks for fifo underruns on GMCH platforms. This needs to be
* done manually on modeset to make sure that we catch all underruns since they
* do not generate an interrupt by themselves on these platforms.
*/
void i9xx_check_fifo_underruns(struct drm_i915_private *dev_priv)
{
struct intel_crtc *crtc;
spin_lock_irq(&dev_priv->irq_lock);
for_each_intel_crtc(dev_priv->dev, crtc) {
u32 reg = PIPESTAT(crtc->pipe);
u32 pipestat;
if (crtc->cpu_fifo_underrun_disabled)
continue;
pipestat = I915_READ(reg) & 0xffff0000;
if ((pipestat & PIPE_FIFO_UNDERRUN_STATUS) == 0)
continue;
I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
POSTING_READ(reg);
DRM_ERROR("pipe %c underrun\n", pipe_name(crtc->pipe));
}
spin_unlock_irq(&dev_priv->irq_lock);
}
static void i9xx_set_fifo_underrun_reporting(struct drm_device *dev,
enum pipe pipe,
bool enable, bool old)
{
struct drm_i915_private *dev_priv = dev->dev_private;
u32 reg = PIPESTAT(pipe);
u32 pipestat = I915_READ(reg) & 0xffff0000;
assert_spin_locked(&dev_priv->irq_lock);
if (enable) {
I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
POSTING_READ(reg);
} else {
if (old && pipestat & PIPE_FIFO_UNDERRUN_STATUS)
DRM_ERROR("pipe %c underrun\n", pipe_name(pipe));
}
}
static void ironlake_set_fifo_underrun_reporting(struct drm_device *dev,
enum pipe pipe, bool enable)
{
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t bit = (pipe == PIPE_A) ? DE_PIPEA_FIFO_UNDERRUN :
DE_PIPEB_FIFO_UNDERRUN;
if (enable)
ironlake_enable_display_irq(dev_priv, bit);
else
ironlake_disable_display_irq(dev_priv, bit);
}
static void ivybridge_set_fifo_underrun_reporting(struct drm_device *dev,
enum pipe pipe,
bool enable, bool old)
{
struct drm_i915_private *dev_priv = dev->dev_private;
if (enable) {
I915_WRITE(GEN7_ERR_INT, ERR_INT_FIFO_UNDERRUN(pipe));
if (!ivb_can_enable_err_int(dev))
return;
ironlake_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
} else {
ironlake_disable_display_irq(dev_priv, DE_ERR_INT_IVB);
if (old &&
I915_READ(GEN7_ERR_INT) & ERR_INT_FIFO_UNDERRUN(pipe)) {
DRM_ERROR("uncleared fifo underrun on pipe %c\n",
pipe_name(pipe));
}
}
}
static void broadwell_set_fifo_underrun_reporting(struct drm_device *dev,
enum pipe pipe, bool enable)
{
struct drm_i915_private *dev_priv = dev->dev_private;
assert_spin_locked(&dev_priv->irq_lock);
if (enable)
dev_priv->de_irq_mask[pipe] &= ~GEN8_PIPE_FIFO_UNDERRUN;
else
dev_priv->de_irq_mask[pipe] |= GEN8_PIPE_FIFO_UNDERRUN;
I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]);
POSTING_READ(GEN8_DE_PIPE_IMR(pipe));
}
static void ibx_set_fifo_underrun_reporting(struct drm_device *dev,
enum transcoder pch_transcoder,
bool enable)
{
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t bit = (pch_transcoder == TRANSCODER_A) ?
SDE_TRANSA_FIFO_UNDER : SDE_TRANSB_FIFO_UNDER;
if (enable)
ibx_enable_display_interrupt(dev_priv, bit);
else
ibx_disable_display_interrupt(dev_priv, bit);
}
static void cpt_set_fifo_underrun_reporting(struct drm_device *dev,
enum transcoder pch_transcoder,
bool enable, bool old)
{
struct drm_i915_private *dev_priv = dev->dev_private;
if (enable) {
I915_WRITE(SERR_INT,
SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder));
if (!cpt_can_enable_serr_int(dev))
return;
ibx_enable_display_interrupt(dev_priv, SDE_ERROR_CPT);
} else {
ibx_disable_display_interrupt(dev_priv, SDE_ERROR_CPT);
if (old && I915_READ(SERR_INT) &
SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)) {
DRM_ERROR("uncleared pch fifo underrun on pch transcoder %c\n",
transcoder_name(pch_transcoder));
}
}
}
static bool __intel_set_cpu_fifo_underrun_reporting(struct drm_device *dev,
enum pipe pipe, bool enable)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
bool old;
assert_spin_locked(&dev_priv->irq_lock);
old = !intel_crtc->cpu_fifo_underrun_disabled;
intel_crtc->cpu_fifo_underrun_disabled = !enable;
if (HAS_GMCH_DISPLAY(dev))
i9xx_set_fifo_underrun_reporting(dev, pipe, enable, old);
else if (IS_GEN5(dev) || IS_GEN6(dev))
ironlake_set_fifo_underrun_reporting(dev, pipe, enable);
else if (IS_GEN7(dev))
ivybridge_set_fifo_underrun_reporting(dev, pipe, enable, old);
else if (IS_GEN8(dev) || IS_GEN9(dev))
broadwell_set_fifo_underrun_reporting(dev, pipe, enable);
return old;
}
/**
* intel_set_cpu_fifo_underrun_reporting - set cpu fifo underrrun reporting state
* @dev_priv: i915 device instance
* @pipe: (CPU) pipe to set state for
* @enable: whether underruns should be reported or not
*
* This function sets the fifo underrun state for @pipe. It is used in the
* modeset code to avoid false positives since on many platforms underruns are
* expected when disabling or enabling the pipe.
*
* Notice that on some platforms disabling underrun reports for one pipe
* disables for all due to shared interrupts. Actual reporting is still per-pipe
* though.
*
* Returns the previous state of underrun reporting.
*/
bool intel_set_cpu_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
enum pipe pipe, bool enable)
{
unsigned long flags;
bool ret;
spin_lock_irqsave(&dev_priv->irq_lock, flags);
ret = __intel_set_cpu_fifo_underrun_reporting(dev_priv->dev, pipe,
enable);
spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return ret;
}
/**
* intel_set_pch_fifo_underrun_reporting - set PCH fifo underrun reporting state
* @dev_priv: i915 device instance
* @pch_transcoder: the PCH transcoder (same as pipe on IVB and older)
* @enable: whether underruns should be reported or not
*
* This function makes us disable or enable PCH fifo underruns for a specific
* PCH transcoder. Notice that on some PCHs (e.g. CPT/PPT), disabling FIFO
* underrun reporting for one transcoder may also disable all the other PCH
* error interruts for the other transcoders, due to the fact that there's just
* one interrupt mask/enable bit for all the transcoders.
*
* Returns the previous state of underrun reporting.
*/
bool intel_set_pch_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
enum transcoder pch_transcoder,
bool enable)
{
struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pch_transcoder];
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
unsigned long flags;
bool old;
/*
* NOTE: Pre-LPT has a fixed cpu pipe -> pch transcoder mapping, but LPT
* has only one pch transcoder A that all pipes can use. To avoid racy
* pch transcoder -> pipe lookups from interrupt code simply store the
* underrun statistics in crtc A. Since we never expose this anywhere
* nor use it outside of the fifo underrun code here using the "wrong"
* crtc on LPT won't cause issues.
*/
spin_lock_irqsave(&dev_priv->irq_lock, flags);
old = !intel_crtc->pch_fifo_underrun_disabled;
intel_crtc->pch_fifo_underrun_disabled = !enable;
if (HAS_PCH_IBX(dev_priv->dev))
ibx_set_fifo_underrun_reporting(dev_priv->dev, pch_transcoder,
enable);
else
cpt_set_fifo_underrun_reporting(dev_priv->dev, pch_transcoder,
enable, old);
spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
return old;
}
/**
* intel_cpu_fifo_underrun_irq_handler - handle CPU fifo underrun interrupt
* @dev_priv: i915 device instance
* @pipe: (CPU) pipe to set state for
*
* This handles a CPU fifo underrun interrupt, generating an underrun warning
* into dmesg if underrun reporting is enabled and then disables the underrun
* interrupt to avoid an irq storm.
*/
void intel_cpu_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
enum pipe pipe)
{
struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
/* We may be called too early in init, thanks BIOS! */
if (crtc == NULL)
return;
/* GMCH can't disable fifo underruns, filter them. */
if (HAS_GMCH_DISPLAY(dev_priv->dev) &&
to_intel_crtc(crtc)->cpu_fifo_underrun_disabled)
return;
if (intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false))
DRM_ERROR("CPU pipe %c FIFO underrun\n",
pipe_name(pipe));
}
/**
* intel_pch_fifo_underrun_irq_handler - handle PCH fifo underrun interrupt
* @dev_priv: i915 device instance
* @pch_transcoder: the PCH transcoder (same as pipe on IVB and older)
*
* This handles a PCH fifo underrun interrupt, generating an underrun warning
* into dmesg if underrun reporting is enabled and then disables the underrun
* interrupt to avoid an irq storm.
*/
void intel_pch_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
enum transcoder pch_transcoder)
{
if (intel_set_pch_fifo_underrun_reporting(dev_priv, pch_transcoder,
false))
DRM_ERROR("PCH transcoder %c FIFO underrun\n",
transcoder_name(pch_transcoder));
}