drm/radeon/dce2: use 10khz units for audio dto calculation

Avoids overflows on DCE2.x devices. Also clarify the calculation
on other asics.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/radeon/evergreen_hdmi.c b/drivers/gpu/drm/radeon/evergreen_hdmi.c
index b4ab8ce..ed7c8a7 100644 (file)
--- a/drivers/gpu/drm/radeon/evergreen_hdmi.c
+++ b/drivers/gpu/drm/radeon/evergreen_hdmi.c
@@ -154,19 +154,18 @@ static void evergreen_audio_set_dto(struct drm_encoder *encoder, u32 clock)
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
        struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
        struct radeon_crtc *radeon_crtc = to_radeon_crtc(encoder->crtc);
-       u32 base_rate = 48000;
+       u32 base_rate = 24000;
 
        if (!dig || !dig->afmt)
                return;
 
-       /* XXX: properly calculate this */
        /* XXX two dtos; generally use dto0 for hdmi */
        /* Express [24MHz / target pixel clock] as an exact rational
         * number (coefficient of two integer numbers.  DCCG_AUDIO_DTOx_PHASE
         * is the numerator, DCCG_AUDIO_DTOx_MODULE is the denominator
         */
-       WREG32(DCCG_AUDIO_DTO0_PHASE, (base_rate*50) & 0xffffff);
-       WREG32(DCCG_AUDIO_DTO0_MODULE, (clock*100) & 0xffffff);
+       WREG32(DCCG_AUDIO_DTO0_PHASE, base_rate * 100);
+       WREG32(DCCG_AUDIO_DTO0_MODULE, clock * 100);
        WREG32(DCCG_AUDIO_DTO_SOURCE, DCCG_AUDIO_DTO0_SOURCE_SEL(radeon_crtc->crtc_id));
 }
 

diff --git a/drivers/gpu/drm/radeon/r600_hdmi.c b/drivers/gpu/drm/radeon/r600_hdmi.c
index 47f180a..456750a 100644 (file)
--- a/drivers/gpu/drm/radeon/r600_hdmi.c
+++ b/drivers/gpu/drm/radeon/r600_hdmi.c
@@ -232,7 +232,7 @@ void r600_audio_set_dto(struct drm_encoder *encoder, u32 clock)
        struct radeon_device *rdev = dev->dev_private;
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
        struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
-       u32 base_rate = 48000;
+       u32 base_rate = 24000;
 
        if (!dig || !dig->afmt)
                return;
@@ -240,7 +240,6 @@ void r600_audio_set_dto(struct drm_encoder *encoder, u32 clock)
        /* there are two DTOs selected by DCCG_AUDIO_DTO_SELECT.
         * doesn't matter which one you use.  Just use the first one.
         */
-       /* XXX: properly calculate this */
        /* XXX two dtos; generally use dto0 for hdmi */
        /* Express [24MHz / target pixel clock] as an exact rational
         * number (coefficient of two integer numbers.  DCCG_AUDIO_DTOx_PHASE
@@ -250,13 +249,13 @@ void r600_audio_set_dto(struct drm_encoder *encoder, u32 clock)
                /* according to the reg specs, this should DCE3.2 only, but in
                 * practice it seems to cover DCE3.0 as well.
                 */
-               WREG32(DCCG_AUDIO_DTO0_PHASE, base_rate * 50);
+               WREG32(DCCG_AUDIO_DTO0_PHASE, base_rate * 100);
                WREG32(DCCG_AUDIO_DTO0_MODULE, clock * 100);
                WREG32(DCCG_AUDIO_DTO_SELECT, 0); /* select DTO0 */
        } else {
                /* according to the reg specs, this should be DCE2.0 and DCE3.0 */
-               WREG32(AUDIO_DTO, AUDIO_DTO_PHASE(base_rate * 50) |
-                      AUDIO_DTO_MODULE(clock * 100));
+               WREG32(AUDIO_DTO, AUDIO_DTO_PHASE(base_rate / 10) |
+                      AUDIO_DTO_MODULE(clock / 10));
        }
 }