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 51static bool ivb_can_enable_err_int(struct drm_device *dev) 52{ 53 struct drm_i915_private *dev_priv = dev->dev_private; 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 69static bool cpt_can_enable_serr_int(struct drm_device *dev) 70{ 71 struct drm_i915_private *dev_priv = dev->dev_private; 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/** 88 * i9xx_check_fifo_underruns - check for fifo underruns 89 * @dev_priv: i915 device instance 90 * 91 * This function checks for fifo underruns on GMCH platforms. This needs to be 92 * done manually on modeset to make sure that we catch all underruns since they 93 * do not generate an interrupt by themselves on these platforms. 94 */ 95void i9xx_check_fifo_underruns(struct drm_i915_private *dev_priv) 96{ 97 struct intel_crtc *crtc; 98 99 spin_lock_irq(&dev_priv->irq_lock); 100 101 for_each_intel_crtc(dev_priv->dev, crtc) { 102 u32 reg = PIPESTAT(crtc->pipe); 103 u32 pipestat; 104 105 if (crtc->cpu_fifo_underrun_disabled) 106 continue; 107 108 pipestat = I915_READ(reg) & 0xffff0000; 109 if ((pipestat & PIPE_FIFO_UNDERRUN_STATUS) == 0) 110 continue; 111 112 I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS); 113 POSTING_READ(reg); 114 115 DRM_ERROR("pipe %c underrun\n", pipe_name(crtc->pipe)); 116 } 117 118 spin_unlock_irq(&dev_priv->irq_lock); 119} 120 121static void i9xx_set_fifo_underrun_reporting(struct drm_device *dev, 122 enum pipe pipe, 123 bool enable, bool old) 124{ 125 struct drm_i915_private *dev_priv = dev->dev_private; 126 u32 reg = PIPESTAT(pipe); 127 u32 pipestat = I915_READ(reg) & 0xffff0000; 128 129 assert_spin_locked(&dev_priv->irq_lock); 130 131 if (enable) { 132 I915_WRITE(reg, pipestat | PIPE_FIFO_UNDERRUN_STATUS); 133 POSTING_READ(reg); 134 } else { 135 if (old && pipestat & PIPE_FIFO_UNDERRUN_STATUS) 136 DRM_ERROR("pipe %c underrun\n", pipe_name(pipe)); 137 } 138} 139 140static void ironlake_set_fifo_underrun_reporting(struct drm_device *dev, 141 enum pipe pipe, bool enable) 142{ 143 struct drm_i915_private *dev_priv = dev->dev_private; 144 uint32_t bit = (pipe == PIPE_A) ? DE_PIPEA_FIFO_UNDERRUN : 145 DE_PIPEB_FIFO_UNDERRUN; 146 147 if (enable) 148 ironlake_enable_display_irq(dev_priv, bit); 149 else 150 ironlake_disable_display_irq(dev_priv, bit); 151} 152 153static 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 = dev->dev_private; 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 ironlake_enable_display_irq(dev_priv, DE_ERR_INT_IVB); 165 } else { 166 ironlake_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 176static void broadwell_set_fifo_underrun_reporting(struct drm_device *dev, 177 enum pipe pipe, bool enable) 178{ 179 struct drm_i915_private *dev_priv = dev->dev_private; 180 181 assert_spin_locked(&dev_priv->irq_lock); 182 183 if (enable) 184 dev_priv->de_irq_mask[pipe] &= ~GEN8_PIPE_FIFO_UNDERRUN; 185 else 186 dev_priv->de_irq_mask[pipe] |= GEN8_PIPE_FIFO_UNDERRUN; 187 I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]); 188 POSTING_READ(GEN8_DE_PIPE_IMR(pipe)); 189} 190 191static void ibx_set_fifo_underrun_reporting(struct drm_device *dev, 192 enum transcoder pch_transcoder, 193 bool enable) 194{ 195 struct drm_i915_private *dev_priv = dev->dev_private; 196 uint32_t bit = (pch_transcoder == TRANSCODER_A) ? 197 SDE_TRANSA_FIFO_UNDER : SDE_TRANSB_FIFO_UNDER; 198 199 if (enable) 200 ibx_enable_display_interrupt(dev_priv, bit); 201 else 202 ibx_disable_display_interrupt(dev_priv, bit); 203} 204 205static void cpt_set_fifo_underrun_reporting(struct drm_device *dev, 206 enum transcoder pch_transcoder, 207 bool enable, bool old) 208{ 209 struct drm_i915_private *dev_priv = dev->dev_private; 210 211 if (enable) { 212 I915_WRITE(SERR_INT, 213 SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)); 214 215 if (!cpt_can_enable_serr_int(dev)) 216 return; 217 218 ibx_enable_display_interrupt(dev_priv, SDE_ERROR_CPT); 219 } else { 220 ibx_disable_display_interrupt(dev_priv, SDE_ERROR_CPT); 221 222 if (old && I915_READ(SERR_INT) & 223 SERR_INT_TRANS_FIFO_UNDERRUN(pch_transcoder)) { 224 DRM_ERROR("uncleared pch fifo underrun on pch transcoder %c\n", 225 transcoder_name(pch_transcoder)); 226 } 227 } 228} 229 230static bool __intel_set_cpu_fifo_underrun_reporting(struct drm_device *dev, 231 enum pipe pipe, bool enable) 232{ 233 struct drm_i915_private *dev_priv = dev->dev_private; 234 struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe]; 235 struct intel_crtc *intel_crtc = to_intel_crtc(crtc); 236 bool old; 237 238 assert_spin_locked(&dev_priv->irq_lock); 239 240 old = !intel_crtc->cpu_fifo_underrun_disabled; 241 intel_crtc->cpu_fifo_underrun_disabled = !enable; 242 243 if (HAS_GMCH_DISPLAY(dev)) 244 i9xx_set_fifo_underrun_reporting(dev, pipe, enable, old); 245 else if (IS_GEN5(dev) || IS_GEN6(dev)) 246 ironlake_set_fifo_underrun_reporting(dev, pipe, enable); 247 else if (IS_GEN7(dev)) 248 ivybridge_set_fifo_underrun_reporting(dev, pipe, enable, old); 249 else if (IS_GEN8(dev) || IS_GEN9(dev)) 250 broadwell_set_fifo_underrun_reporting(dev, pipe, enable); 251 252 return old; 253} 254 255/** 256 * intel_set_cpu_fifo_underrun_reporting - set cpu fifo underrrun reporting state 257 * @dev_priv: i915 device instance 258 * @pipe: (CPU) pipe to set state for 259 * @enable: whether underruns should be reported or not 260 * 261 * This function sets the fifo underrun state for @pipe. It is used in the 262 * modeset code to avoid false positives since on many platforms underruns are 263 * expected when disabling or enabling the pipe. 264 * 265 * Notice that on some platforms disabling underrun reports for one pipe 266 * disables for all due to shared interrupts. Actual reporting is still per-pipe 267 * though. 268 * 269 * Returns the previous state of underrun reporting. 270 */ 271bool intel_set_cpu_fifo_underrun_reporting(struct drm_i915_private *dev_priv, 272 enum pipe pipe, bool enable) 273{ 274 unsigned long flags; 275 bool ret; 276 277 spin_lock_irqsave(&dev_priv->irq_lock, flags); 278 ret = __intel_set_cpu_fifo_underrun_reporting(dev_priv->dev, pipe, 279 enable); 280 spin_unlock_irqrestore(&dev_priv->irq_lock, flags); 281 282 return ret; 283} 284 285/** 286 * intel_set_pch_fifo_underrun_reporting - set PCH fifo underrun reporting state 287 * @dev_priv: i915 device instance 288 * @pch_transcoder: the PCH transcoder (same as pipe on IVB and older) 289 * @enable: whether underruns should be reported or not 290 * 291 * This function makes us disable or enable PCH fifo underruns for a specific 292 * PCH transcoder. Notice that on some PCHs (e.g. CPT/PPT), disabling FIFO 293 * underrun reporting for one transcoder may also disable all the other PCH 294 * error interruts for the other transcoders, due to the fact that there's just 295 * one interrupt mask/enable bit for all the transcoders. 296 * 297 * Returns the previous state of underrun reporting. 298 */ 299bool intel_set_pch_fifo_underrun_reporting(struct drm_i915_private *dev_priv, 300 enum transcoder pch_transcoder, 301 bool enable) 302{ 303 struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pch_transcoder]; 304 struct intel_crtc *intel_crtc = to_intel_crtc(crtc); 305 unsigned long flags; 306 bool old; 307 308 /* 309 * NOTE: Pre-LPT has a fixed cpu pipe -> pch transcoder mapping, but LPT 310 * has only one pch transcoder A that all pipes can use. To avoid racy 311 * pch transcoder -> pipe lookups from interrupt code simply store the 312 * underrun statistics in crtc A. Since we never expose this anywhere 313 * nor use it outside of the fifo underrun code here using the "wrong" 314 * crtc on LPT won't cause issues. 315 */ 316 317 spin_lock_irqsave(&dev_priv->irq_lock, flags); 318 319 old = !intel_crtc->pch_fifo_underrun_disabled; 320 intel_crtc->pch_fifo_underrun_disabled = !enable; 321 322 if (HAS_PCH_IBX(dev_priv->dev)) 323 ibx_set_fifo_underrun_reporting(dev_priv->dev, pch_transcoder, 324 enable); 325 else 326 cpt_set_fifo_underrun_reporting(dev_priv->dev, pch_transcoder, 327 enable, old); 328 329 spin_unlock_irqrestore(&dev_priv->irq_lock, flags); 330 return old; 331} 332 333/** 334 * intel_cpu_fifo_underrun_irq_handler - handle CPU fifo underrun interrupt 335 * @dev_priv: i915 device instance 336 * @pipe: (CPU) pipe to set state for 337 * 338 * This handles a CPU fifo underrun interrupt, generating an underrun warning 339 * into dmesg if underrun reporting is enabled and then disables the underrun 340 * interrupt to avoid an irq storm. 341 */ 342void intel_cpu_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv, 343 enum pipe pipe) 344{ 345 struct drm_crtc *crtc = dev_priv->pipe_to_crtc_mapping[pipe]; 346 347 /* We may be called too early in init, thanks BIOS! */ 348 if (crtc == NULL) 349 return; 350 351 /* GMCH can't disable fifo underruns, filter them. */ 352 if (HAS_GMCH_DISPLAY(dev_priv->dev) && 353 to_intel_crtc(crtc)->cpu_fifo_underrun_disabled) 354 return; 355 356 if (intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false)) 357 DRM_ERROR("CPU pipe %c FIFO underrun\n", 358 pipe_name(pipe)); 359} 360 361/** 362 * intel_pch_fifo_underrun_irq_handler - handle PCH fifo underrun interrupt 363 * @dev_priv: i915 device instance 364 * @pch_transcoder: the PCH transcoder (same as pipe on IVB and older) 365 * 366 * This handles a PCH fifo underrun interrupt, generating an underrun warning 367 * into dmesg if underrun reporting is enabled and then disables the underrun 368 * interrupt to avoid an irq storm. 369 */ 370void intel_pch_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv, 371 enum transcoder pch_transcoder) 372{ 373 if (intel_set_pch_fifo_underrun_reporting(dev_priv, pch_transcoder, 374 false)) 375 DRM_ERROR("PCH transcoder %c FIFO underrun\n", 376 transcoder_name(pch_transcoder)); 377} 378