drm/i915/ddi: Optimize mtl_port_buf_ctl_program

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@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250103051705.145161-3-suraj.kandpal@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 654980d7fc3d6e683c9795dc8ea250aa37dedd51..483d9e5da586fc828855e5fcb77140857e899cc7 100644 (file)
--- 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)