From ebeac38025ff36b76b0f6fa0aeb52729e96bb6bc Mon Sep 17 00:00:00 2001 From: Madhav Chauhan Date: Fri, 17 Feb 2017 18:13:35 +0530 Subject: [PATCH] drm/i915/glk: Validate only DSI PORT A PLL divider As per BSPEC, GLK supports MIPI DSI 8X clk only on PORT A. Therefore only for PORT A PLL divider value should be validated. Signed-off-by: Madhav Chauhan Reviewed-by: Jani Nikula Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1487335415-14766-8-git-send-email-madhav.chauhan@intel.com --- drivers/gpu/drm/i915/intel_dsi_pll.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c index 7a7617b24cb2..2ff2ee7f3b78 100644 --- a/drivers/gpu/drm/i915/intel_dsi_pll.c +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c @@ -206,17 +206,24 @@ static bool bxt_dsi_pll_is_enabled(struct drm_i915_private *dev_priv) return false; /* - * Both dividers must be programmed with valid values even if only one - * of the PLL is used, see BSpec/Broxton Clocks. Check this here for + * Dividers must be programmed with valid values. As per BSEPC, for + * GEMINLAKE only PORT A divider values are checked while for BXT + * both divider values are validated. Check this here for * paranoia, since BIOS is known to misconfigure PLLs in this way at * times, and since accessing DSI registers with invalid dividers * causes a system hang. */ val = I915_READ(BXT_DSI_PLL_CTL); - if (!(val & BXT_DSIA_16X_MASK) || !(val & BXT_DSIC_16X_MASK)) { - DRM_DEBUG_DRIVER("PLL is enabled with invalid divider settings (%08x)\n", - val); - enabled = false; + if (IS_GEMINILAKE(dev_priv)) { + if (!(val & BXT_DSIA_16X_MASK)) { + DRM_DEBUG_DRIVER("Invalid PLL divider (%08x)\n", val); + enabled = false; + } + } else { + if (!(val & BXT_DSIA_16X_MASK) || !(val & BXT_DSIC_16X_MASK)) { + DRM_DEBUG_DRIVER("Invalid PLL divider (%08x)\n", val); + enabled = false; + } } return enabled; -- 2.20.1