On Thu, Mar 02, 2017 at 08:27:54PM +0300, Alexey Brodkin wrote:
> 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 <abrod...@synopsys.com>
> Cc: Daniel Vetter <daniel.vet...@ffwll.ch>
> Cc: David Airlie <airl...@linux.ie>
> Cc: Jose Abreu <joab...@synopsys.com>
> ---
> 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)
This isn't required at all, see drm_crtc_state.adjusted_mode. Just update
that and you're good - .mode_fixup is the backwards compatibility function
for old kms drivers, atomic_check is strictly more powerful.
Please also make sure the documentation properly explains this, and if
not, please submit a patch to improve it.
-Daniel
> {
> 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
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
