Re: [PATCH 1/3] drm/i915/dsb: Introduce intel_dsb_poll()

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 1/31/2025 12:15 AM, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Add a functiuon for emitting a DSB poll instruction. We'll allow

s/functiuon/function


> the caller to specify the poll parameters.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_dsb.c | 19 +++++++++++++++++++
>   drivers/gpu/drm/i915/display/intel_dsb.h |  3 +++
>   2 files changed, 22 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
> index 2f2812c23972..b68ee125afae 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.c
> @@ -452,6 +452,25 @@ void intel_dsb_wait_scanline_out(struct intel_atomic_state *state,
>   			   start, end);
>   }
>   
> +void intel_dsb_poll(struct intel_dsb *dsb,
> +		    i915_reg_t reg, u32 mask, u32 val,
> +		    int wait, int count)

Perhaps `wait_us` to convey that value is in microseconds.

In any case change LGTM.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>

> +{
> +	struct intel_crtc *crtc = dsb->crtc;
> +	enum pipe pipe = crtc->pipe;
> +
> +	intel_dsb_reg_write(dsb, DSB_POLLMASK(pipe, dsb->id), mask);
> +	intel_dsb_reg_write(dsb, DSB_POLLFUNC(pipe, dsb->id),
> +			    DSB_POLL_ENABLE |
> +			    DSB_POLL_WAIT(wait) | DSB_POLL_COUNT(count));
> +
> +	intel_dsb_noop(dsb, 5);
> +
> +	intel_dsb_emit(dsb, val,
> +		       (DSB_OPCODE_POLL << DSB_OPCODE_SHIFT) |
> +		       i915_mmio_reg_offset(reg));
> +}
> +
>   static void intel_dsb_align_tail(struct intel_dsb *dsb)
>   {
>   	u32 aligned_tail, tail;
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
> index da6df07a3c83..4511d1a1a187 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.h
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.h
> @@ -54,6 +54,9 @@ void intel_dsb_wait_scanline_out(struct intel_atomic_state *state,
>   				 int lower, int upper);
>   void intel_dsb_vblank_evade(struct intel_atomic_state *state,
>   			    struct intel_dsb *dsb);
> +void intel_dsb_poll(struct intel_dsb *dsb,
> +		    i915_reg_t reg, u32 mask, u32 val,
> +		    int wait, int count);
>   void intel_dsb_chain(struct intel_atomic_state *state,
>   		     struct intel_dsb *dsb,
>   		     struct intel_dsb *chained_dsb,