drivers/gpu/drm/i915/intel_fifo_underrun.c

   1 /*
   2  * Copyright © 2014 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Daniel Vetter <daniel.vetter@ffwll.ch>
  25  *
  26  */
  27
  28 #include "i915_drv.h"
  29 #include "intel_drv.h"
  30
  31 /**
  32  * DOC: fifo underrun handling
  33  *
  34  * The i915 driver checks for display fifo underruns using the interrupt signals
  35  * provided by the hardware. This is enabled by default and fairly useful to
  36  * debug display issues, especially watermark settings.
  37  *
  38  * If an underrun is detected this is logged into dmesg. To avoid flooding logs
  39  * and occupying the cpu underrun interrupts are disabled after the first
  40  * occurrence until the next modeset on a given pipe.
  41  *
  42  * Note that underrun detection on gmch platforms is a bit more ugly since there
  43  * is no interrupt (despite that the signalling bit is in the PIPESTAT pipe
  44  * interrupt register). Also on some other platforms underrun interrupts are
  45  * shared, which means that if we detect an underrun we need to disable underrun
  46  * reporting on all pipes.
  47  *
  48  * The code also supports underrun detection on the PCH transcoder.
  49  */
  50
  51 static bool ivb_can_enable_err_int(struct drm_device *dev)
  52 {
  53         struct drm_i915_private *dev_priv = to_i915(dev);
  54         struct intel_crtc *crtc;
  55         enum pipe pipe;
  56
  57         assert_spin_locked(&dev_priv->irq_lock);
  58
  59         for_each_pipe(dev_priv, pipe) {
  60                 crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
  61
  62                 if (crtc->cpu_fifo_underrun_disabled)
  63                         return false;
  64         }
  65
  66         return true;
  67 }
  68
  69 static bool cpt_can_enable_serr_int(struct drm_device *dev)
  70 {
  71         struct drm_i915_private *dev_priv = to_i915(dev);
  72         enum pipe pipe;
  73         struct intel_crtc *crtc;
  74
  75         assert_spin_locked(&dev_priv->irq_lock);
  76
  77         for_each_pipe(dev_priv, pipe) {
  78                 crtc = to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
  79
  80                 if (crtc->pch_fifo_underrun_disabled)
  81                         return false;
  82         }
  83
  84         return true;
  85 }
  86
  87 static void i9xx_check_fifo_underruns(struct intel_crtc *crtc)
  88 {
  89         struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
  90         i915_reg_t reg = PIPESTAT(crtc->pipe);
  91         u32 pipestat = I915_READ(reg) & 0xffff0000;
  92
  93         assert_spin_locked(&dev_priv->irq_lock);
  94
  95         if ((pipestat & PIPE_FIFO_UNDERRUN_STATUS) == 0)
  96                 return;
  97
  98         I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
  99         POSTING_READ(reg);
 100
 101         DRM_ERROR("pipe %c underrun\n", pipe_name(crtc->pipe));
 102 }
 103
 104 static void i9xx_set_fifo_underrun_reporting(struct drm_device *dev,
 105                                              enum pipe pipe,
 106                                              bool enable, bool old)
 107 {
 108         struct drm_i915_private *dev_priv = to_i915(dev);
 109         i915_reg_t reg = PIPESTAT(pipe);
 110         u32 pipestat = I915_READ(reg) & 0xffff0000;
 111
 112         assert_spin_locked(&dev_priv->irq_lock);
 113
 114         if (enable) {
 115                 I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS);
 116                 POSTING_READ(reg);
 117         } else {
 118                 if (old && pipestat & PIPE_FIFO_UNDERRUN_STATUS)
 119                         DRM_ERROR("pipe %c underrun\n", pipe_name(pipe));
 120         }
 121 }
 122
 123 static void ironlake_set_fifo_underrun_reporting(struct drm_device *dev,
 124                                                  enum pipe pipe, bool enable)
 125 {
 126         struct drm_i915_private *dev_priv = to_i915(dev);
 127         uint32_t bit = (pipe == PIPE_A) ? DE_PIPEA_FIFO_UNDERRUN :
 128                                           DE_PIPEB_FIFO_UNDERRUN;
 129
 130         if (enable)
 131                 ilk_enable_display_irq(dev_priv, bit);
 132         else
 133                 ilk_disable_display_irq(dev_priv, bit);
 134 }
 135
 136 static void ivybridge_check_fifo_underruns(struct intel_crtc *crtc)
 137 {
 138         struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 139         enum pipe pipe = crtc->pipe;
 140         uint32_t err_int = I915_READ(GEN7_ERR_INT);
 141
 142         assert_spin_locked(&dev_priv->irq_lock);
 143
 144         if ((err_int & ERR_INT_FIFO_UNDERRUN(pipe)) == 0)
 145                 return;
 146
 147         I915_WRITE(GEN7_ERR_INT, ERR_INT_FIFO_UNDERRUN(pipe));
 148         POSTING_READ(GEN7_ERR_INT);
 149
 150         DRM_ERROR("fifo underrun on pipe %c\n", pipe_name(pipe));
 151 }
 152
 153 static void ivybridge_set_fifo_underrun_reporting(struct drm_device *dev,
 154                                                   enum pipe pipe,
 155                                                   bool enable, bool old)
 156 {
 157         struct drm_i915_private *dev_priv = to_i915(dev);
 158         if (enable) {
 159                 I915_WRITE(GEN7_ERR_INT, ERR_INT_FIFO_UNDERRUN(pipe));
 160
 161                 if (!ivb_can_enable_err_int(dev))
 162                         return;
 163
 164                 ilk_enable_display_irq(dev_priv, DE_ERR_INT_IVB);
 165         } else {
 166                 ilk_disable_display_irq(dev_priv, DE_ERR_INT_IVB);
 167
 168                 if (old &&
 169                     I915_READ(GEN7_ERR_INT) & ERR_INT_FIFO_UNDERRUN(pipe)) {
 170                         DRM_ERROR("uncleared fifo underrun on pipe %c\n",
 171                                   pipe_name(pipe));
 172                 }
 173         }
 174 }
 175
 176 static void broadwell_set_fifo_underrun_reporting(struct drm_device *dev,
 177                                                   enum pipe pipe, bool enable)
 178 {
 179         struct drm_i915_private *dev_priv = to_i915(dev);
 180
 181         if (enable)
 182                 bdw_enable_pipe_irq(dev_priv, pipe, GEN8_PIPE_FIFO_UNDERRUN);
 183         else
 184                 bdw_disable_pipe_irq(dev_priv, pipe, GEN8_PIPE_FIFO_UNDERRUN);
 185 }
 186
 187 static void ibx_set_fifo_underrun_reporting(struct drm_device *dev,
 188                                             enum transcoder pch_transcoder,
 189                                             bool enable)
 190 {
 191         struct drm_i915_private *dev_priv = to_i915(dev);
 192         uint32_t bit = (pch_transcoder == TRANSCODER_A) ?
 193                        SDE_TRANSA_FIFO_UNDER : SDE_TRANSB_FIFO_UNDER;
 194
 195         if (enable)
 196                 ibx_enable_display_interrupt(dev_priv, bit);
 197         else
 198                 ibx_disable_display_interrupt(dev_priv, bit);
 199 }
 200
 201 static void cpt_check_pch_fifo_underruns(struct intel_crtc *crtc)
 202 {
 203         struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 204         enum transcoder pch_transcoder = (enum transcoder) crtc->pipe;
 205         uint32_t serr_int = I915_READ(SERR_INT);
 206
 207         assert_spin_locked(&dev_priv->irq_lock);
 208
 209         if ((serr_int & SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)) == 0)
 210                 return;
 211
 212         I915_WRITE(SERR_INT, SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder));
 213         POSTING_READ(SERR_INT);
 214
 215         DRM_ERROR("pch fifo underrun on pch transcoder %s\n",
 216                   transcoder_name(pch_transcoder));
 217 }
 218
 219 static void cpt_set_fifo_underrun_reporting(struct drm_device *dev,
 220                                             enum transcoder pch_transcoder,
 221                                             bool enable, bool old)
 222 {
 223         struct drm_i915_private *dev_priv = to_i915(dev);
 224
 225         if (enable) {
 226                 I915_WRITE(SERR_INT,
 227                            SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder));
 228
 229                 if (!cpt_can_enable_serr_int(dev))
 230                         return;
 231
 232                 ibx_enable_display_interrupt(dev_priv, SDE_ERROR_CPT);
 233         } else {
 234                 ibx_disable_display_interrupt(dev_priv, SDE_ERROR_CPT);
 235
 236                 if (old && I915_READ(SERR_INT) &
 237                     SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)) {
 238                         DRM_ERROR("uncleared pch fifo underrun on pch transcoder %s\n",
 239                                   transcoder_name(pch_transcoder));
 240                 }
 241         }
 242 }
 243
 244 static bool __intel_set_cpu_fifo_underrun_reporting(struct drm_device *dev,
 245                                                     enum pipe pipe, bool enable)
 246 {
 247         struct drm_i915_private *dev_priv = to_i915(dev);
 248         struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
 249         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 250         bool old;
 251
 252         assert_spin_locked(&dev_priv->irq_lock);
 253
 254         old = !intel_crtc->cpu_fifo_underrun_disabled;
 255         intel_crtc->cpu_fifo_underrun_disabled = !enable;
 256
 257         if (HAS_GMCH_DISPLAY(dev))
 258                 i9xx_set_fifo_underrun_reporting(dev, pipe, enable, old);
 259         else if (IS_GEN5(dev) || IS_GEN6(dev))
 260                 ironlake_set_fifo_underrun_reporting(dev, pipe, enable);
 261         else if (IS_GEN7(dev))
 262                 ivybridge_set_fifo_underrun_reporting(dev, pipe, enable, old);
 263         else if (IS_GEN8(dev) || IS_GEN9(dev))
 264                 broadwell_set_fifo_underrun_reporting(dev, pipe, enable);
 265
 266         return old;
 267 }
 268
 269 /**
 270  * intel_set_cpu_fifo_underrun_reporting - set cpu fifo underrrun reporting state
 271  * @dev_priv: i915 device instance
 272  * @pipe: (CPU) pipe to set state for
 273  * @enable: whether underruns should be reported or not
 274  *
 275  * This function sets the fifo underrun state for @pipe. It is used in the
 276  * modeset code to avoid false positives since on many platforms underruns are
 277  * expected when disabling or enabling the pipe.
 278  *
 279  * Notice that on some platforms disabling underrun reports for one pipe
 280  * disables for all due to shared interrupts. Actual reporting is still per-pipe
 281  * though.
 282  *
 283  * Returns the previous state of underrun reporting.
 284  */
 285 bool intel_set_cpu_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
 286                                            enum pipe pipe, bool enable)
 287 {
 288         unsigned long flags;
 289         bool ret;
 290
 291         spin_lock_irqsave(&dev_priv->irq_lock, flags);
 292         ret = __intel_set_cpu_fifo_underrun_reporting(&dev_priv->drm, pipe,
 293                                                       enable);
 294         spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
 295
 296         return ret;
 297 }
 298
 299 /**
 300  * intel_set_pch_fifo_underrun_reporting - set PCH fifo underrun reporting state
 301  * @dev_priv: i915 device instance
 302  * @pch_transcoder: the PCH transcoder (same as pipe on IVB and older)
 303  * @enable: whether underruns should be reported or not
 304  *
 305  * This function makes us disable or enable PCH fifo underruns for a specific
 306  * PCH transcoder. Notice that on some PCHs (e.g. CPT/PPT), disabling FIFO
 307  * underrun reporting for one transcoder may also disable all the other PCH
 308  * error interruts for the other transcoders, due to the fact that there's just
 309  * one interrupt mask/enable bit for all the transcoders.
 310  *
 311  * Returns the previous state of underrun reporting.
 312  */
 313 bool intel_set_pch_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
 314                                            enum transcoder pch_transcoder,
 315                                            bool enable)
 316 {
 317         struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pch_transcoder];
 318         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 319         unsigned long flags;
 320         bool old;
 321
 322         /*
 323          * NOTE: Pre-LPT has a fixed cpu pipe -> pch transcoder mapping, but LPT
 324          * has only one pch transcoder A that all pipes can use. To avoid racy
 325          * pch transcoder -> pipe lookups from interrupt code simply store the
 326          * underrun statistics in crtc A. Since we never expose this anywhere
 327          * nor use it outside of the fifo underrun code here using the "wrong"
 328          * crtc on LPT won't cause issues.
 329          */
 330
 331         spin_lock_irqsave(&dev_priv->irq_lock, flags);
 332
 333         old = !intel_crtc->pch_fifo_underrun_disabled;
 334         intel_crtc->pch_fifo_underrun_disabled = !enable;
 335
 336         if (HAS_PCH_IBX(dev_priv))
 337                 ibx_set_fifo_underrun_reporting(&dev_priv->drm,
 338                                                 pch_transcoder,
 339                                                 enable);
 340         else
 341                 cpt_set_fifo_underrun_reporting(&dev_priv->drm,
 342                                                 pch_transcoder,
 343                                                 enable, old);
 344
 345         spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
 346         return old;
 347 }
 348
 349 /**
 350  * intel_cpu_fifo_underrun_irq_handler - handle CPU fifo underrun interrupt
 351  * @dev_priv: i915 device instance
 352  * @pipe: (CPU) pipe to set state for
 353  *
 354  * This handles a CPU fifo underrun interrupt, generating an underrun warning
 355  * into dmesg if underrun reporting is enabled and then disables the underrun
 356  * interrupt to avoid an irq storm.
 357  */
 358 void intel_cpu_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
 359                                          enum pipe pipe)
 360 {
 361         struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe];
 362
 363         /* We may be called too early in init, thanks BIOS! */
 364         if (crtc == NULL)
 365                 return;
 366
 367         /* GMCH can't disable fifo underruns, filter them. */
 368         if (HAS_GMCH_DISPLAY(dev_priv) &&
 369             to_intel_crtc(crtc)->cpu_fifo_underrun_disabled)
 370                 return;
 371
 372         if (intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false))
 373                 DRM_ERROR("CPU pipe %c FIFO underrun\n",
 374                           pipe_name(pipe));
 375 }
 376
 377 /**
 378  * intel_pch_fifo_underrun_irq_handler - handle PCH fifo underrun interrupt
 379  * @dev_priv: i915 device instance
 380  * @pch_transcoder: the PCH transcoder (same as pipe on IVB and older)
 381  *
 382  * This handles a PCH fifo underrun interrupt, generating an underrun warning
 383  * into dmesg if underrun reporting is enabled and then disables the underrun
 384  * interrupt to avoid an irq storm.
 385  */
 386 void intel_pch_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
 387                                          enum transcoder pch_transcoder)
 388 {
 389         if (intel_set_pch_fifo_underrun_reporting(dev_priv, pch_transcoder,
 390                                                   false))
 391                 DRM_ERROR("PCH transcoder %s FIFO underrun\n",
 392                           transcoder_name(pch_transcoder));
 393 }
 394
 395 /**
 396  * intel_check_cpu_fifo_underruns - check for CPU fifo underruns immediately
 397  * @dev_priv: i915 device instance
 398  *
 399  * Check for CPU fifo underruns immediately. Useful on IVB/HSW where the shared
 400  * error interrupt may have been disabled, and so CPU fifo underruns won't
 401  * necessarily raise an interrupt, and on GMCH platforms where underruns never
 402  * raise an interrupt.
 403  */
 404 void intel_check_cpu_fifo_underruns(struct drm_i915_private *dev_priv)
 405 {
 406         struct intel_crtc *crtc;
 407
 408         spin_lock_irq(&dev_priv->irq_lock);
 409
 410         for_each_intel_crtc(&dev_priv->drm, crtc) {
 411                 if (crtc->cpu_fifo_underrun_disabled)
 412                         continue;
 413
 414                 if (HAS_GMCH_DISPLAY(dev_priv))
 415                         i9xx_check_fifo_underruns(crtc);
 416                 else if (IS_GEN7(dev_priv))
 417                         ivybridge_check_fifo_underruns(crtc);
 418         }
 419
 420         spin_unlock_irq(&dev_priv->irq_lock);
 421 }
 422
 423 /**
 424  * intel_check_pch_fifo_underruns - check for PCH fifo underruns immediately
 425  * @dev_priv: i915 device instance
 426  *
 427  * Check for PCH fifo underruns immediately. Useful on CPT/PPT where the shared
 428  * error interrupt may have been disabled, and so PCH fifo underruns won't
 429  * necessarily raise an interrupt.
 430  */
 431 void intel_check_pch_fifo_underruns(struct drm_i915_private *dev_priv)
 432 {
 433         struct intel_crtc *crtc;
 434
 435         spin_lock_irq(&dev_priv->irq_lock);
 436
 437         for_each_intel_crtc(&dev_priv->drm, crtc) {
 438                 if (crtc->pch_fifo_underrun_disabled)
 439                         continue;
 440
 441                 if (HAS_PCH_CPT(dev_priv))
 442                         cpt_check_pch_fifo_underruns(crtc);
 443         }
 444
 445         spin_unlock_irq(&dev_priv->irq_lock);
 446 }