hdmi = HDMI0_ERROR_ACK | HDMI0_ENABLE;
                switch (radeon_encoder->encoder_id) {
                case ENCODER_OBJECT_ID_INTERNAL_KLDSCP_TMDS1:
-                       WREG32_P(AVIVO_TMDSA_CNTL, AVIVO_TMDSA_CNTL_HDMI_EN,
-                                ~AVIVO_TMDSA_CNTL_HDMI_EN);
+                       WREG32_OR(AVIVO_TMDSA_CNTL, AVIVO_TMDSA_CNTL_HDMI_EN);
                        hdmi |= HDMI0_STREAM(HDMI0_STREAM_TMDSA);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_LVTM1:
-                       WREG32_P(AVIVO_LVTMA_CNTL, AVIVO_LVTMA_CNTL_HDMI_EN,
-                                ~AVIVO_LVTMA_CNTL_HDMI_EN);
+                       WREG32_OR(AVIVO_LVTMA_CNTL, AVIVO_LVTMA_CNTL_HDMI_EN);
                        hdmi |= HDMI0_STREAM(HDMI0_STREAM_LVTMA);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_DDI:
-                       WREG32_P(DDIA_CNTL, DDIA_HDMI_EN, ~DDIA_HDMI_EN);
+                       WREG32_OR(DDIA_CNTL, DDIA_HDMI_EN);
                        hdmi |= HDMI0_STREAM(HDMI0_STREAM_DDIA);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_KLDSCP_DVO1:
        if (rdev->family >= CHIP_R600 && !ASIC_IS_DCE3(rdev)) {
                switch (radeon_encoder->encoder_id) {
                case ENCODER_OBJECT_ID_INTERNAL_KLDSCP_TMDS1:
-                       WREG32_P(AVIVO_TMDSA_CNTL, 0,
-                                ~AVIVO_TMDSA_CNTL_HDMI_EN);
+                       WREG32_AND(AVIVO_TMDSA_CNTL, ~AVIVO_TMDSA_CNTL_HDMI_EN);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_LVTM1:
-                       WREG32_P(AVIVO_LVTMA_CNTL, 0,
-                                ~AVIVO_LVTMA_CNTL_HDMI_EN);
+                       WREG32_AND(AVIVO_LVTMA_CNTL, ~AVIVO_LVTMA_CNTL_HDMI_EN);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_DDI:
-                       WREG32_P(DDIA_CNTL, 0, ~DDIA_HDMI_EN);
+                       WREG32_AND(DDIA_CNTL, ~DDIA_HDMI_EN);
                        break;
                case ENCODER_OBJECT_ID_INTERNAL_KLDSCP_DVO1:
                        break;
 
                tmp_ |= ((val) & ~(mask));                      \
                WREG32(reg, tmp_);                              \
        } while (0)
+#define WREG32_AND(reg, and) WREG32_P(reg, 0, and)
+#define WREG32_OR(reg, or) WREG32_P(reg, or, ~or)
 #define WREG32_PLL_P(reg, val, mask)                           \
        do {                                                    \
                uint32_t tmp_ = RREG32_PLL(reg);                \