From 16e849145dc2ba9d9fc2027c530fc0a682d5ae61 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Fri, 17 Feb 2017 17:39:45 +0200 Subject: [PATCH] drm/i915: Preserve the state of power wells not explicitly enabled MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Atm, power wells that BIOS has enabled, but which we don't explicitly enable during power domain initialization would get disabled as we clear the BIOS request bit in the given power well sync_hw hook. To prevent this copy over any set request bits in the BIOS request register to the driver request register and clear the BIOS request bit only afterwards. This doesn't make a difference now, since we enable all power wells during power domain initialization. A follow-up patchset will add power wells for which this isn't true, so fix up the inconsistency. Cc: Ander Conselvan de Oliveira Cc: David Weinehall Cc: Ville Syrjälä Signed-off-by: Imre Deak Reviewed-by: Ander Conselvan de Oliveira Link: http://patchwork.freedesktop.org/patch/msgid/1487345986-26511-5-git-send-email-imre.deak@intel.com --- drivers/gpu/drm/i915/intel_runtime_pm.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index 62c99a96c8e7..44d4da3ad7a1 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -830,12 +830,14 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv, static void hsw_power_well_sync_hw(struct drm_i915_private *dev_priv, struct i915_power_well *power_well) { - /* - * We're taking over the BIOS, so clear any requests made by it since - * the driver is in charge now. - */ - if (I915_READ(HSW_PWR_WELL_BIOS) & HSW_PWR_WELL_ENABLE_REQUEST) + /* Take over the request bit if set by BIOS. */ + if (I915_READ(HSW_PWR_WELL_BIOS) & HSW_PWR_WELL_ENABLE_REQUEST) { + if (!(I915_READ(HSW_PWR_WELL_DRIVER) & + HSW_PWR_WELL_ENABLE_REQUEST)) + I915_WRITE(HSW_PWR_WELL_DRIVER, + HSW_PWR_WELL_ENABLE_REQUEST); I915_WRITE(HSW_PWR_WELL_BIOS, 0); + } } static void hsw_power_well_enable(struct drm_i915_private *dev_priv, @@ -865,8 +867,12 @@ static void skl_power_well_sync_hw(struct drm_i915_private *dev_priv, uint32_t mask = SKL_POWER_WELL_REQ(power_well->id); uint32_t bios_req = I915_READ(HSW_PWR_WELL_BIOS); - /* Clear any request made by BIOS as driver is taking over */ + /* Take over the request bit if set by BIOS. */ if (bios_req & mask) { + uint32_t drv_req = I915_READ(HSW_PWR_WELL_DRIVER); + + if (!(drv_req & mask)) + I915_WRITE(HSW_PWR_WELL_DRIVER, drv_req | mask); I915_WRITE(HSW_PWR_WELL_BIOS, bios_req & ~mask); } } -- 2.20.1