lkml.org 
[lkml]   [2017]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [PATCH] drm/arcpgu: use .mode_fixup instead of .atomic_check
    Date
    Hi Daniel,

    On Thu, 2017-03-02 at 20:54 +0100, Daniel Vetter wrote:
    > 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 <abrodkin@synopsys.com>
    > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    > > Cc: David Airlie <airlied@linux.ie>
    > > Cc: Jose Abreu <joabreu@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.

    So if I understood you correct here what I really need is just to get rid of existing check,
    right? I.e. the following is to be in v2 respin:
    ------------------------------->8-------------------------------
    diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c
    index ad9a95916f1f..86f1555914e8 100644
    --- a/drivers/gpu/drm/arc/arcpgu_crtc.c
    +++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
    @@ -129,20 +129,6 @@ 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)
    -{
    -       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;
    -
    -       return 0;
    -}
    -
     static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
                                          struct drm_crtc_state *state)
     {
    @@ -165,7 +151,6 @@ 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,
     };
    ------------------------------->8-------------------------------

    > Please also make sure the documentation properly explains this, and if
    > not, please submit a patch to improve it.

    You mean explains what? That .mode_fixup is not meant to be used in
    new code?

    -Alexey
    \
     
     \ /
      Last update: 2017-03-03 14:28    [W:2.794 / U:0.164 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site