[PATCH v6 1/5] drm/vc4: Move the DSI clock divider workaround closer to the clock call.

Eric Anholt
2017-08-15T23:53:08Z

We want the adjusted_mode->clock to be the actual clock we're
expecting to program, so that consumers see the right values for clock
and vrefresh.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
drivers/gpu/drm/vc4/vc4_dsi.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index d1e0dc908048..eb787eed8abe 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -859,11 +859,7 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
pll_clock = parent_rate / divider;
pixel_clock_hz = pll_clock / dsi->divider;

- /* Round up the clk_set_rate() request slightly, since
- * PLLD_DSI1 is an integer divider and its rate selection will
- * never round up.
- */
- adjusted_mode->clock = pixel_clock_hz / 1000 + 1;
+ adjusted_mode->clock = pixel_clock_hz / 1000;

/* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal);
@@ -900,7 +896,11 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
vc4_dsi_dump_regs(dsi);
}

- phy_clock = pixel_clock_hz * dsi->divider;
+ /* Round up the clk_set_rate() request slightly, since
+ * PLLD_DSI1 is an integer divider and its rate selection will
+ * never round up.
+ */
+ phy_clock = (pixel_clock_hz + 1000) * dsi->divider;
ret = clk_set_rate(dsi->pll_phy_clock, phy_clock);
if (ret) {
dev_err(&dsi->pdev->dev,
--
2.14.1