This reverts commit 73867c8709b5 ("drm/i915/display: Remove check for low voltage sku for max dp source rate"), which, on an i7-11850H iGPU with a Thinkpad X1 Extreme Gen 4, attached to a LG LP160UQ1-SPB1 embedded panel, causes wild flickering glitching technicolor pyrotechnics on resumption from suspend. The display shows strobing colors in an utter disaster explosion of pantone, as though bombs were dropped on the leprechauns at the base of the rainbow. Rebooting the machine fixes the issue, presumably because the display is initialized by firmware rather than by i915. Otherwise, the GPU appears to work fine. Bisection traced it back to this commit, which makes sense given the issues. Note: This re-opens, and puts back to the drawing board, https://gitlab.freedesktop.org/drm/intel/-/issues/5272 which was fixed by the regressing commit.
Unified · Split
| @@ -388,13 +388,23 @@ static int dg2_max_source_rate(struct intel_dp *intel_dp) · 387 unmodified lines | ||
| 388 | 388 | return intel_dp_is_edp(intel_dp) ? 810000 : 1350000; |
| 389 | 389 | } |
| 390 | 390 | |
| 391 | +static bool is_low_voltage_sku(struct drm_i915_private *i915, enum phy phy) | |
| 392 | +{ | |
| 393 | + u32 voltage; | |
| 394 | + | |
| 395 | + voltage = intel_de_read(i915, ICL_PORT_COMP_DW3(phy)) & VOLTAGE_INFO_MASK; | |
| 396 | + | |
| 397 | + return voltage == VOLTAGE_INFO_0_85V; | |
| 398 | +} | |
| 399 | + | |
| 391 | 400 | static int icl_max_source_rate(struct intel_dp *intel_dp) |
| 392 | 401 | { |
| 393 | 402 | struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); |
| 394 | 403 | struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); |
| 395 | 404 | enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port); |
| 396 | 405 | |
| 397 | − if (intel_phy_is_combo(dev_priv, phy) && !intel_dp_is_edp(intel_dp)) | |
| 406 | + if (intel_phy_is_combo(dev_priv, phy) && | |
| 407 | + (is_low_voltage_sku(dev_priv, phy) || !intel_dp_is_edp(intel_dp))) | |
| 398 | 408 | return 540000; |
| 399 | 409 | |
| 400 | 410 | return 810000; |
| @@ -402,7 +412,23 @@ static int icl_max_source_rate(struct intel_dp *intel_dp) · 1 unmodified line | ||
| 402 | 412 | |
| 403 | 413 | static int ehl_max_source_rate(struct intel_dp *intel_dp) |
| 404 | 414 | { |
| 405 | − if (intel_dp_is_edp(intel_dp)) | |
| 415 | + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); | |
| 416 | + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); | |
| 417 | + enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port); | |
| 418 | + | |
| 419 | + if (intel_dp_is_edp(intel_dp) || is_low_voltage_sku(dev_priv, phy)) | |
| 420 | + return 540000; | |
| 421 | + | |
| 422 | + return 810000; | |
| 423 | +} | |
| 424 | + | |
| 425 | +static int dg1_max_source_rate(struct intel_dp *intel_dp) | |
| 426 | +{ | |
| 427 | + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); | |
| 428 | + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); | |
| 429 | + enum phy phy = intel_port_to_phy(i915, dig_port->base.port); | |
| 430 | + | |
| 431 | + if (intel_phy_is_combo(i915, phy) && is_low_voltage_sku(i915, phy)) | |
| 406 | 432 | return 540000; |
| 407 | 433 | |
| 408 | 434 | return 810000; |
| @@ -445,7 +471,7 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp) · 36 unmodified lines | ||
| 445 | 471 | max_rate = dg2_max_source_rate(intel_dp); |
| 446 | 472 | else if (IS_ALDERLAKE_P(dev_priv) || IS_ALDERLAKE_S(dev_priv) || |
| 447 | 473 | IS_DG1(dev_priv) || IS_ROCKETLAKE(dev_priv)) |
| 448 | − max_rate = 810000; | |
| 474 | + max_rate = dg1_max_source_rate(intel_dp); | |
| 449 | 475 | else if (IS_JSL_EHL(dev_priv)) |
| 450 | 476 | max_rate = ehl_max_source_rate(intel_dp); |
| 451 | 477 | else |