On Wed, Aug 26, 2015 at 01:36:07AM +0530, Animesh Manna wrote:
> Mmio register access after dc6/dc5 entry is not allowed when
> DC6 power states are enabled according to bspec (bspec-id 0527),
> so enabling dc6 as the last call in suspend flow.
We unconditionaly grab a power well reference for everything in our
suspend/resume functions, which means dc6/5 should be prevented for long
enough.
Also since dc6/5 are part of the power well framework you can't just
enable/disable them directly, instead you need to get/put the
corresponding power wells.
Finally this patch doesn't just do that, but also frobs around a lot in
set power well code itself, and I have no idea what it does there and why.
It does smell a bit like you're just breaking dc6 for runtime pm though,
which wouldn't be good.
Anyway I decided to just merge this since this patch series has been
floating around since forever, but then the patch didn't apply cleanly and
so dropped it.
-Daniel
>
> v1: Initial version.
>
> v2: Based on review comment from Daniel,
> - created a seperate patch for csr uninitialization set call.
>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> Cc: Damien Lespiau <damien.lespiau@xxxxxxxxx>
> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> Cc: Sunil Kamath <sunil.kamath@xxxxxxxxx>
> Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
> Signed-off-by: Vathsala Nagaraju <vathsala.nagaraju@xxxxxxxxx>
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 13 +++++++++++++
> drivers/gpu/drm/i915/intel_drv.h | 2 ++
> drivers/gpu/drm/i915/intel_runtime_pm.c | 19 +++++++------------
> 3 files changed, 22 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 478101c..fa66162 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1013,10 +1013,20 @@ static int i915_pm_resume(struct device *dev)
>
> static int skl_suspend_complete(struct drm_i915_private *dev_priv)
> {
> + enum csr_state state;
> /* Enabling DC6 is not a hard requirement to enter runtime D3 */
>
> skl_uninit_cdclk(dev_priv);
>
> + /* TODO: wait for a completion event or
> + * similar here instead of busy
> + * waiting using wait_for function.
> + */
> + wait_for((state = intel_csr_load_status_get(dev_priv)) !=
> + FW_UNINITIALIZED, 1000);
> + if (state == FW_LOADED)
> + skl_enable_dc6(dev_priv);
> +
> return 0;
> }
>
> @@ -1063,6 +1073,9 @@ static int skl_resume_prepare(struct drm_i915_private *dev_priv)
> {
> struct drm_device *dev = dev_priv->dev;
>
> + if (intel_csr_load_status_get(dev_priv) == FW_LOADED)
> + skl_disable_dc6(dev_priv);
> +
> skl_init_cdclk(dev_priv);
> intel_csr_load_program(dev);
>
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 81b7d77..9cb7d4e 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1118,6 +1118,8 @@ void bxt_enable_dc9(struct drm_i915_private *dev_priv);
> void bxt_disable_dc9(struct drm_i915_private *dev_priv);
> void skl_init_cdclk(struct drm_i915_private *dev_priv);
> void skl_uninit_cdclk(struct drm_i915_private *dev_priv);
> +void skl_enable_dc6(struct drm_i915_private *dev_priv);
> +void skl_disable_dc6(struct drm_i915_private *dev_priv);
> void intel_dp_get_m_n(struct intel_crtc *crtc,
> struct intel_crtc_state *pipe_config);
> void intel_dp_set_m_n(struct intel_crtc *crtc, enum link_m_n_set m_n);
> diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
> index 821644d..23a3aa3 100644
> --- a/drivers/gpu/drm/i915/intel_runtime_pm.c
> +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
> @@ -548,7 +548,7 @@ static void assert_can_disable_dc6(struct drm_i915_private *dev_priv)
> "DC6 already programmed to be disabled.\n");
> }
>
> -static void skl_enable_dc6(struct drm_i915_private *dev_priv)
> +void skl_enable_dc6(struct drm_i915_private *dev_priv)
> {
> uint32_t val;
>
> @@ -565,7 +565,7 @@ static void skl_enable_dc6(struct drm_i915_private *dev_priv)
> POSTING_READ(DC_STATE_EN);
> }
>
> -static void skl_disable_dc6(struct drm_i915_private *dev_priv)
> +void skl_disable_dc6(struct drm_i915_private *dev_priv)
> {
> uint32_t val;
>
> @@ -626,10 +626,10 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> !I915_READ(HSW_PWR_WELL_BIOS),
> "Invalid for power well status to be enabled, unless done by the BIOS, \
> when request is to disable!\n");
> - if ((GEN9_ENABLE_DC5(dev) || SKL_ENABLE_DC6(dev)) &&
> - power_well->data == SKL_DISP_PW_2) {
> + if (power_well->data == SKL_DISP_PW_2) {
> + if (GEN9_ENABLE_DC5(dev))
> + gen9_disable_dc5(dev_priv);
> if (SKL_ENABLE_DC6(dev)) {
> - skl_disable_dc6(dev_priv);
> /*
> * DDI buffer programming unnecessary during driver-load/resume
> * as it's already done during modeset initialization then.
> @@ -637,8 +637,6 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> */
> if (!dev_priv->power_domains.initializing)
> intel_prepare_ddi(dev);
> - } else {
> - gen9_disable_dc5(dev_priv);
> }
> }
> I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
> @@ -658,7 +656,7 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> POSTING_READ(HSW_PWR_WELL_DRIVER);
> DRM_DEBUG_KMS("Disabling %s\n", power_well->name);
>
> - if ((GEN9_ENABLE_DC5(dev) || SKL_ENABLE_DC6(dev)) &&
> + if (GEN9_ENABLE_DC5(dev) &&
> power_well->data == SKL_DISP_PW_2) {
> enum csr_state state;
> /* TODO: wait for a completion event or
> @@ -671,10 +669,7 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
> DRM_ERROR("CSR firmware not ready (%d)\n",
> state);
> else
> - if (SKL_ENABLE_DC6(dev))
> - skl_enable_dc6(dev_priv);
> - else
> - gen9_enable_dc5(dev_priv);
> + gen9_enable_dc5(dev_priv);
> }
> }
> }
> --
> 2.0.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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