diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 508838e..d5b8368 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1623,44 +1623,67 @@ static struct intel_watermark_params igd_cursor_hplloff_wm = { IGD_FIFO_LINE_SIZE }; static struct intel_watermark_params i945_wm_info = { - I915_FIFO_LINE_SIZE, + I945_FIFO_SIZE, I915_MAX_WM, 1, - 0, - IGD_FIFO_LINE_SIZE + 2, + I915_FIFO_LINE_SIZE }; static struct intel_watermark_params i915_wm_info = { - I945_FIFO_SIZE, + I915_FIFO_SIZE, I915_MAX_WM, 1, - 0, + 2, I915_FIFO_LINE_SIZE }; static struct intel_watermark_params i855_wm_info = { I855GM_FIFO_SIZE, I915_MAX_WM, 1, - 0, + 2, I830_FIFO_LINE_SIZE }; static struct intel_watermark_params i830_wm_info = { I830_FIFO_SIZE, I915_MAX_WM, 1, - 0, + 2, I830_FIFO_LINE_SIZE }; +/** + * intel_calculate_wm - calculate watermark level + * @clock_in_khz: pixel clock + * @wm: chip FIFO params + * @pixel_size: display pixel size + * @latency_ns: memory latency for the platform + * + * Calculate the watermark level (the level at which the display plane will + * start fetching from memory again). Each chip has a different display + * FIFO size and allocation, so the caller needs to figure that out and pass + * in the correct intel_watermark_params structure. + * + * As the pixel clock runs, the FIFO will be drained at a rate that depends + * on the pixel size. When it reaches the watermark level, it'll start + * fetching FIFO line sized based chunks from memory until the FIFO fills + * past the watermark point. If the FIFO drains completely, a FIFO underrun + * will occur, and a display engine hang could result. + */ static unsigned long intel_calculate_wm(unsigned long clock_in_khz, struct intel_watermark_params *wm, int pixel_size, unsigned long latency_ns) { - unsigned long bytes_required, wm_size; + unsigned long entries_required, wm_size; + + entries_required = (clock_in_khz * pixel_size * latency_ns) / 1000000; + entries_required /= wm->cacheline_size; + + DRM_DEBUG("FIFO entries required for mode: %d\n", entries_required); + + wm_size = wm->fifo_size - (entries_required + wm->guard_size); - bytes_required = (clock_in_khz * pixel_size * latency_ns) / 1000000; - bytes_required /= wm->cacheline_size; - wm_size = wm->fifo_size - bytes_required - wm->guard_size; + DRM_DEBUG("FIFO watermark level: %d\n", wm_size); if (wm_size > wm->max_wm) wm_size = wm->max_wm; @@ -1799,7 +1822,7 @@ static void igd_enable_cxsr(struct drm_device *dev, unsigned long clock, return; } -const static int latency_ns = 5000; /* default for non-igd platforms */ +const static int latency_ns = 3000; /* default for non-igd platforms */ static void i965_update_wm(struct drm_device *dev) @@ -1817,55 +1840,46 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock, int planeb_clock, int sr_hdisplay, int pixel_size) { struct drm_i915_private *dev_priv = dev->dev_private; - uint32_t fwater_lo = I915_READ(FW_BLC) & MM_FIFO_WATERMARK; - uint32_t fwater_hi = I915_READ(FW_BLC2) & LM_FIFO_WATERMARK; - int bsize, asize, cwm, bwm = 1, awm = 1, srwm = 1; + uint32_t fwater_lo; + uint32_t fwater_hi; + int total_size, cacheline_size, cwm, srwm = 1; uint32_t dsparb = I915_READ(DSPARB); - int planea_entries, planeb_entries; - struct intel_watermark_params *wm_params; + int planea_wm, planeb_wm; + struct intel_watermark_params pipea_params, pipeb_params; unsigned long line_time_us; int sr_clock, sr_entries = 0; if (IS_I965GM(dev) || IS_I945GM(dev)) - wm_params = &i945_wm_info; + pipea_params = pipeb_params = i945_wm_info; else if (IS_I9XX(dev)) - wm_params = &i915_wm_info; + pipea_params = pipeb_params = i915_wm_info; else - wm_params = &i855_wm_info; - - planea_entries = intel_calculate_wm(planea_clock, wm_params, - pixel_size, latency_ns); - planeb_entries = intel_calculate_wm(planeb_clock, wm_params, - pixel_size, latency_ns); + pipea_params = pipeb_params = i855_wm_info; - DRM_DEBUG("FIFO entries - A: %d, B: %d\n", planea_entries, - planeb_entries); + /* Grab a couple of global values before we overwrite them */ + total_size = pipea_params.fifo_size; + cacheline_size = pipea_params.cacheline_size; if (IS_I9XX(dev)) { - asize = dsparb & 0x7f; - bsize = (dsparb >> DSPARB_CSTART_SHIFT) & 0x7f; + pipea_params.fifo_size = dsparb & 0x7f; + pipeb_params.fifo_size = + ((dsparb >> DSPARB_CSTART_SHIFT) & 0x7f) - + (dsparb & 0x7f); } else { - asize = dsparb & 0x1ff; - bsize = (dsparb >> DSPARB_BEND_SHIFT) & 0x1ff; + pipea_params.fifo_size = dsparb & 0x1ff; + pipeb_params.fifo_size = + ((dsparb >> DSPARB_BEND_SHIFT) & 0x1ff) - + (dsparb & 0x1ff); } - DRM_DEBUG("FIFO size - A: %d, B: %d\n", asize, bsize); - - /* Two extra entries for padding */ - awm = asize - (planea_entries + 2); - bwm = bsize - (planeb_entries + 2); + DRM_DEBUG("FIFO size - (0x%08x) A: %d, B: %d\n", dsparb, + pipea_params.fifo_size, + pipeb_params.fifo_size); - /* Sanity check against potentially bad FIFO allocations */ - if (awm <= 0) { - /* pipe is on but has too few FIFO entries */ - if (planea_entries != 0) - DRM_DEBUG("plane A needs more FIFO entries\n"); - awm = 1; - } - if (bwm <= 0) { - if (planeb_entries != 0) - DRM_DEBUG("plane B needs more FIFO entries\n"); - bwm = 1; - } + planea_wm = intel_calculate_wm(planea_clock, &pipea_params, + pixel_size, latency_ns); + planeb_wm = intel_calculate_wm(planeb_clock, &pipeb_params, + pixel_size, latency_ns); + DRM_DEBUG("FIFO watermarks - A: %d, B: %d\n", planea_wm, planeb_wm); /* * Overlay gets an aggressive default since video jitter is bad. @@ -1874,25 +1888,36 @@ static void i9xx_update_wm(struct drm_device *dev, int planea_clock, /* Calc sr entries for one pipe configs */ if (!planea_clock || !planeb_clock) { + /* self-refresh has much higher latency */ + const static int sr_latency_ns = 6000; + sr_clock = planea_clock ? planea_clock : planeb_clock; - line_time_us = (sr_hdisplay * 1000) / sr_clock; - sr_entries = (((latency_ns / line_time_us) + 1) * pixel_size * - sr_hdisplay) / 1000; - sr_entries = roundup(sr_entries / wm_params->cacheline_size, 1); - if (sr_entries < wm_params->fifo_size) - srwm = wm_params->fifo_size - sr_entries; + line_time_us = ((sr_hdisplay * 1000) / sr_clock); + + /* Use ns/us then divide to preserve precision */ + sr_entries = (((sr_latency_ns / line_time_us) + 1) * + pixel_size * sr_hdisplay) / 1000; + sr_entries = roundup(sr_entries / cacheline_size, 1); + DRM_DEBUG("self-refresh entries: %d\n", sr_entries); + srwm = total_size - sr_entries; + if (srwm < 0) + srwm = 1; } DRM_DEBUG("Setting FIFO watermarks - A: %d, B: %d, C: %d, SR %d\n", - awm, bwm, cwm, srwm); + planea_wm, planeb_wm, cwm, srwm); + + fwater_lo = ((planeb_wm & 0x3f) << 16) | (planea_wm & 0x3f); + fwater_hi = (cwm & 0x1f); - fwater_lo = fwater_lo | ((bwm & 0x3f) << 16) | (awm & 0x3f); - fwater_hi = fwater_hi | (cwm & 0x1f); + /* Set request length to 8 cachelines per fetch */ + fwater_lo = fwater_lo | (1 << 24) | (1 << 8); + fwater_hi = fwater_hi | (1 << 8); I915_WRITE(FW_BLC, fwater_lo); I915_WRITE(FW_BLC2, fwater_hi); if (IS_I9XX(dev)) - I915_WRITE(FW_BLC_SELF, FW_BLC_SELF_EN | (srwm & 0x3f)); + I915_WRITE(FW_BLC_SELF, (srwm & 0x3f)); } static void i830_update_wm(struct drm_device *dev, int planea_clock, @@ -1901,17 +1926,15 @@ static void i830_update_wm(struct drm_device *dev, int planea_clock, struct drm_i915_private *dev_priv = dev->dev_private; uint32_t dsparb = I915_READ(DSPARB); uint32_t fwater_lo = I915_READ(FW_BLC) & MM_FIFO_WATERMARK; - unsigned int asize, awm; - int planea_entries; - - planea_entries = intel_calculate_wm(planea_clock, &i830_wm_info, - pixel_size, latency_ns); + unsigned int asize; + int planea_wm; asize = dsparb & 0x7f; + i830_wm_info.fifo_size = asize; - awm = asize - planea_entries; - - fwater_lo = fwater_lo | awm; + planea_wm = intel_calculate_wm(planea_clock, &i830_wm_info, + pixel_size, latency_ns); + fwater_lo = fwater_lo | planea_wm; I915_WRITE(FW_BLC, fwater_lo); }