--- /dev/null
+/*
+ * 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));
+}
Code Review / kvmfornfv.git / blobdiff