[PATCH 2/2] drm/i915/ddi: Optimize mtl_port_buf_ctl_program

[Jani Nikula]

On Fri, 03 Jan 2025, Suraj Kandpal <suraj.kandpal at intel.com> wrote:
> A small optimization and cleanup for mtl_port_buf_ctl_program function
> which lets use intel_de_rmw instead of a intel_de_read and
> intel_de_write.
>
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>

Reviewed-by: Jani Nikula <jani.nikula at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 5e944cae116a..c3c8a1d255a1 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2537,13 +2537,10 @@ static void mtl_port_buf_ctl_program(struct intel_encoder *encoder,
>  	struct intel_display *display = to_intel_display(encoder);
>  	struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
>  	enum port port = encoder->port;
> -	u32 val;
> +	u32 val = 0;
>  
> -	val = intel_de_read(display, XELPDP_PORT_BUF_CTL1(i915, port));
> -	val &= ~XELPDP_PORT_WIDTH_MASK;
>  	val |= XELPDP_PORT_WIDTH(mtl_get_port_width(crtc_state->lane_count));
>  
> -	val &= ~XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK;
>  	if (intel_dp_is_uhbr(crtc_state))
>  		val |= XELPDP_PORT_BUF_PORT_DATA_40BIT;
>  	else
> @@ -2552,7 +2549,9 @@ static void mtl_port_buf_ctl_program(struct intel_encoder *encoder,
>  	if (dig_port->lane_reversal)
>  		val |= XELPDP_PORT_REVERSAL;
>  
> -	intel_de_write(display, XELPDP_PORT_BUF_CTL1(display, port), val);
> +	intel_de_rmw(display, XELPDP_PORT_BUF_CTL1(display, port),
> +		     XELPDP_PORT_WIDTH_MASK | XELPDP_PORT_BUF_PORT_DATA_WIDTH_MASK,
> +		     val);
>  }
>  
>  static void mtl_port_buf_ctl_io_selection(struct intel_encoder *encoder)

-- 
Jani Nikula, Intel