drm/i915: Add a module option to override the use of SSC
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
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0de75a2..72fea2b 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -49,6 +49,9 @@
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);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 385fc7e..5969f46 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -954,6 +954,7 @@
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);
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index b0b1200..0b44956 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -264,17 +264,12 @@
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;
}
}
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 25d9688..98967f3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3822,6 +3822,11 @@
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,
@@ -3884,7 +3889,7 @@
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);
@@ -4059,7 +4064,7 @@
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);
@@ -4070,13 +4075,13 @@
/* 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;
}
@@ -4104,7 +4109,7 @@
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;
@@ -4183,7 +4188,7 @@
/* 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;