[PATCH] drm/arcpgu: use .mode_fixup instead of .atomic_check

From: Alexey Brodkin
Date: Thu Mar 02 2017 - 12:28:41 EST


Since we cannot always generate exactly requested pixel clock
there's not much sense in checking requested_clock == clk_round_rate().
In that case for quite some modes we'll be getting -EINVAL and no video
output at all.

But given there's some tolerance to real pixel clock in TVs/monitors
we may still give it a try with the clock as close to requested one as
PLL on the board may generate. So we just do a fixup to what current
board may provide.

Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Jose Abreu <joabreu@xxxxxxxxxxxx>
---
drivers/gpu/drm/arc/arcpgu_crtc.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c
index ad9a95916f1f..3f2823c1efc3 100644
--- a/drivers/gpu/drm/arc/arcpgu_crtc.c
+++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
@@ -129,18 +129,16 @@ static void arc_pgu_crtc_disable(struct drm_crtc *crtc)
~ARCPGU_CTRL_ENABLE_MASK);
}

-static int arc_pgu_crtc_atomic_check(struct drm_crtc *crtc,
- struct drm_crtc_state *state)
+static bool arc_pgu_crtc_mode_fixup(struct drm_crtc *crtc,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
{
struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
- struct drm_display_mode *mode = &state->adjusted_mode;
- long rate, clk_rate = mode->clock * 1000;

- rate = clk_round_rate(arcpgu->clk, clk_rate);
- if (rate != clk_rate)
- return -EINVAL;
+ adjusted_mode->clock =
+ clk_round_rate(arcpgu->clk, mode->clock * 1000) / 1000;

- return 0;
+ return true;
}

static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
@@ -165,8 +163,8 @@ static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
.disable = arc_pgu_crtc_disable,
.prepare = arc_pgu_crtc_disable,
.commit = arc_pgu_crtc_enable,
- .atomic_check = arc_pgu_crtc_atomic_check,
.atomic_begin = arc_pgu_crtc_atomic_begin,
+ .mode_fixup = arc_pgu_crtc_mode_fixup,
};

static void arc_pgu_plane_atomic_update(struct drm_plane *plane,
--
2.7.4