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drm/i915: Add a module option to override the use of SSC
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In order to workaround the issue with LVDS not working on the Lenovo
U160 apparently due to using the wrong SSC frequency, add an option to
disable SSC.

Suggested-by: Lukács, Árpád <lukacs.arpad@gmail.com>
Bugzillla: https://bugs.freedesktop.org/show_bug.cgi?id=32748
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
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Chris Wilson committed Jan 13, 2011
1 parent c8303e7 commit a761503
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Showing 4 changed files with 21 additions and 17 deletions.
3 changes: 3 additions & 0 deletions drivers/gpu/drm/i915/i915_drv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,9 @@ module_param_named(powersave, i915_powersave, int, 0600);
unsigned int i915_lvds_downclock = 0;
module_param_named(lvds_downclock, i915_lvds_downclock, int, 0400);

unsigned int i915_panel_use_ssc = 1;
module_param_named(lvds_use_ssc, i915_panel_use_ssc, int, 0600);

bool i915_try_reset = true;
module_param_named(reset, i915_try_reset, bool, 0600);

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1 change: 1 addition & 0 deletions drivers/gpu/drm/i915/i915_drv.h
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Original file line number Diff line number Diff line change
Expand Up @@ -954,6 +954,7 @@ extern int i915_max_ioctl;
extern unsigned int i915_fbpercrtc;
extern unsigned int i915_powersave;
extern unsigned int i915_lvds_downclock;
extern unsigned int i915_panel_use_ssc;

extern int i915_suspend(struct drm_device *dev, pm_message_t state);
extern int i915_resume(struct drm_device *dev);
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17 changes: 6 additions & 11 deletions drivers/gpu/drm/i915/intel_bios.c
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Original file line number Diff line number Diff line change
Expand Up @@ -264,17 +264,12 @@ parse_general_features(struct drm_i915_private *dev_priv,
dev_priv->int_crt_support = general->int_crt_support;
dev_priv->lvds_use_ssc = general->enable_ssc;

if (dev_priv->lvds_use_ssc) {
if (IS_I85X(dev))
dev_priv->lvds_ssc_freq =
general->ssc_freq ? 66 : 48;
else if (IS_GEN5(dev) || IS_GEN6(dev))
dev_priv->lvds_ssc_freq =
general->ssc_freq ? 100 : 120;
else
dev_priv->lvds_ssc_freq =
general->ssc_freq ? 100 : 96;
}
if (IS_I85X(dev))
dev_priv->lvds_ssc_freq = general->ssc_freq ? 66 : 48;
else if (IS_GEN5(dev) || IS_GEN6(dev))
dev_priv->lvds_ssc_freq = general->ssc_freq ? 100 : 120;
else
dev_priv->lvds_ssc_freq = general->ssc_freq ? 100 : 96;
}
}

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17 changes: 11 additions & 6 deletions drivers/gpu/drm/i915/intel_display.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3822,6 +3822,11 @@ static void intel_update_watermarks(struct drm_device *dev)
sr_hdisplay, sr_htotal, pixel_size);
}

static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)
{
return dev_priv->lvds_use_ssc && i915_panel_use_ssc;
}

static int intel_crtc_mode_set(struct drm_crtc *crtc,
struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode,
Expand Down Expand Up @@ -3884,7 +3889,7 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
num_connectors++;
}

if (is_lvds && dev_priv->lvds_use_ssc && num_connectors < 2) {
if (is_lvds && intel_panel_use_ssc(dev_priv) && num_connectors < 2) {
refclk = dev_priv->lvds_ssc_freq * 1000;
DRM_DEBUG_KMS("using SSC reference clock of %d MHz\n",
refclk / 1000);
Expand Down Expand Up @@ -4059,7 +4064,7 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
udelay(200);

if (has_edp_encoder) {
if (dev_priv->lvds_use_ssc) {
if (intel_panel_use_ssc(dev_priv)) {
temp |= DREF_SSC1_ENABLE;
I915_WRITE(PCH_DREF_CONTROL, temp);

Expand All @@ -4070,13 +4075,13 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,

/* Enable CPU source on CPU attached eDP */
if (!intel_encoder_is_pch_edp(&has_edp_encoder->base)) {
if (dev_priv->lvds_use_ssc)
if (intel_panel_use_ssc(dev_priv))
temp |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD;
else
temp |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD;
} else {
/* Enable SSC on PCH eDP if needed */
if (dev_priv->lvds_use_ssc) {
if (intel_panel_use_ssc(dev_priv)) {
DRM_ERROR("enabling SSC on PCH\n");
temp |= DREF_SUPERSPREAD_SOURCE_ENABLE;
}
Expand Down Expand Up @@ -4104,7 +4109,7 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
int factor = 21;

if (is_lvds) {
if ((dev_priv->lvds_use_ssc &&
if ((intel_panel_use_ssc(dev_priv) &&
dev_priv->lvds_ssc_freq == 100) ||
(I915_READ(PCH_LVDS) & LVDS_CLKB_POWER_MASK) == LVDS_CLKB_POWER_UP)
factor = 25;
Expand Down Expand Up @@ -4183,7 +4188,7 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
/* XXX: just matching BIOS for now */
/* dpll |= PLL_REF_INPUT_TVCLKINBC; */
dpll |= 3;
else if (is_lvds && dev_priv->lvds_use_ssc && num_connectors < 2)
else if (is_lvds && intel_panel_use_ssc(dev_priv) && num_connectors < 2)
dpll |= PLLB_REF_INPUT_SPREADSPECTRUMIN;
else
dpll |= PLL_REF_INPUT_DREFCLK;
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