[Intel-gfx] [PATCH 1/2] drm/i915: Fix power domain reference balance when DMC firmware is not present

[Imre Deak]

On Mon, Oct 15, 2018 at 06:29:45PM -0700, José Roberto de Souza wrote:
> intel_csr_ucode_init() gets a POWER_DOMAIN_INIT reference but it is
> only released in csr_load_work_fn() if DMC firmware is present in
> filesystem, keeping a reference to POWER_DOMAIN_INIT and every power
> well enabled all the times.
> 
> Cc: Imre Deak <imre.deak at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_csr.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_csr.c b/drivers/gpu/drm/i915/intel_csr.c
> index fc7bd21fa586..7c91a56869e9 100644
> --- a/drivers/gpu/drm/i915/intel_csr.c
> +++ b/drivers/gpu/drm/i915/intel_csr.c
> @@ -423,8 +423,6 @@ static void csr_load_work_fn(struct work_struct *work)
>  	if (dev_priv->csr.dmc_payload) {
>  		intel_csr_load_program(dev_priv);
>  
> -		intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);
> -
>  		DRM_INFO("Finished loading DMC firmware %s (v%u.%u)\n",
>  			 dev_priv->csr.fw_path,
>  			 CSR_VERSION_MAJOR(csr->version),

and for the !dmc_payload case below we print:

    "Failed to load DMC firmware, disabling runtime power management."

explaining why we hold on to the reference in that case.

> @@ -439,6 +437,8 @@ static void csr_load_work_fn(struct work_struct *work)
>  	}
>  
>  	release_firmware(fw);
> +
> +	intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);
>  }
>  
>  /**
> -- 
> 2.19.1
>