drm/vc4: Move the DSI clock divider workaround closer to the clock call.

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>
Link: https://patchwork.freedesktop.org/patch/msgid/20170815234722.20700-1-eric@anholt.net
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
(cherry picked from commit d409eeafa9ba1c0f2eb75a2619fc787808a545e4)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index f5cf11dff45b1814752ce11d0cb7ad051888e4bf..5c46910f359deebbe46fc3e573be3d1f1f29eda1 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -953,11 +953,7 @@ 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 = adjusted_mode->clock * mode->htotal /
@@ -1001,7 +997,11 @@ 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,