SWF18 is set if the display has been intialized by the pre-os. It also gives what configuration is enabled on which pipe. The DPLL and CDCLK verification checks can fail as the pre-os does initialize the DPLL for Audio codec initialization. So fisrt check if SWF18 is set and then follow through with other DPLL and CDCLK verification.
Cc: Ville Syrjälä <[email protected]> Signed-off-by: Shobhit Kumar <[email protected]> --- drivers/gpu/drm/i915/i915_reg.h | 3 +++ drivers/gpu/drm/i915/intel_display.c | 8 ++++++++ 2 files changed, 11 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 9ee9481..bd476ff 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -5006,6 +5006,9 @@ enum skl_disp_power_wells { #define SWF1(i) (dev_priv->info.display_mmio_offset + 0x71410 + (i) * 4) #define SWF3(i) (dev_priv->info.display_mmio_offset + 0x72414 + (i) * 4) +/* VBIOS flag for display initialized status */ +#define GEN6_SWF18 (dev_priv->info.display_mmio_offset + 0x4F060) + /* Pipe B */ #define _PIPEBDSL (dev_priv->info.display_mmio_offset + 0x71000) #define _PIPEBCONF (dev_priv->info.display_mmio_offset + 0x71008) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 103cacb..0ecb35c 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -5761,6 +5761,14 @@ int skl_sanitize_cdclk(struct drm_i915_private *dev_priv) uint32_t cdctl = I915_READ(CDCLK_CTL); int freq = dev_priv->skl_boot_cdclk; + /* + * check if the pre-os intialized the display + * There is SWF18 scratchpad register defined which is set by the + * pre-os which can be used by the OS drivers to check the status + */ + if ((I915_READ(GEN6_SWF18) & 0x00FFFF) == 0) + goto sanitize; + /* Is PLL enabled and locked ? */ if (!((lcpll1 & LCPLL_PLL_ENABLE) && (lcpll1 & LCPLL_PLL_LOCK))) goto sanitize; -- 2.4.3 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
