[Intel-gfx] [PATCH v3 2/4] drm/i915: Always set HUC_LOADING_AGENT_GUC bit in WOPCM offset register

[Michal Wajdeczko]

On Tue, 10 Apr 2018 02:42:18 +0200, Jackie Li <yaodong.li at intel.com> wrote:

> The enable_guc modparam is used to enable/disable GuC/HuC FW uploading
> dynamcially during i915 module loading. If WOPCM offset register was
   ^^^^
typo

> locked
> without having HUC_LOADING_AGENT_GUC bit set to 1, the module reloading
> with both GuC and HuC FW will fail since we need to set this bit to 1 for
> HuC FW uploading.
>
> Since HUC_LOADING_AGENT_GUC bit has no impact on GuC FW uploading, this
> patch updates the register updating code to make sure the WOPCM offset
> register is always locked with HUC_LOADING_AGENT_GUC bit set to 1 which
> will guarantee successful uploading of both GuC and HuC FW. We will  
> further
> take care of the locked values in the following enhancement patch.
>
> Signed-off-by: Jackie Li <yaodong.li at intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> Cc: Michal Winiarski <michal.winiarski at intel.com>
> Cc: John Spotswood <john.a.spotswood at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_wopcm.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_wopcm.c  
> b/drivers/gpu/drm/i915/intel_wopcm.c
> index 74bf76f..b1c08ca 100644
> --- a/drivers/gpu/drm/i915/intel_wopcm.c
> +++ b/drivers/gpu/drm/i915/intel_wopcm.c
> @@ -238,8 +238,6 @@ static inline int write_and_verify(struct  
> drm_i915_private *dev_priv,
>  int intel_wopcm_init_hw(struct intel_wopcm *wopcm)
>  {
>  	struct drm_i915_private *dev_priv = wopcm_to_i915(wopcm);
> -	u32 huc_agent;
> -	u32 mask;
>  	int err;
> 	if (!USES_GUC(dev_priv))
> @@ -255,10 +253,10 @@ int intel_wopcm_init_hw(struct intel_wopcm *wopcm)
>  	if (err)
>  		goto err_out;
> -	huc_agent = USES_HUC(dev_priv) ? HUC_LOADING_AGENT_GUC : 0;
> -	mask = GUC_WOPCM_OFFSET_MASK | GUC_WOPCM_OFFSET_VALID | huc_agent;
>  	err = write_and_verify(dev_priv, DMA_GUC_WOPCM_OFFSET,
> -			       wopcm->guc.base | huc_agent, mask,
> +			       wopcm->guc.base | HUC_LOADING_AGENT_GUC,
> +			       GUC_WOPCM_OFFSET_MASK | HUC_LOADING_AGENT_GUC |
> +			       GUC_WOPCM_OFFSET_VALID,

while we can unconditionally set HUC_AGENT bit, there is no need to verify
it unless we are using HuC, so we can consider leaving old mask intact.

/m

>  			       GUC_WOPCM_OFFSET_VALID);
>  	if (err)
>  		goto err_out;