| Message ID | bf5c60fb64278fc4894098f50add801f6365d823.1498574041.git.joabreu@synopsys.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Jose, On Tue, 2017-06-27 at 15:36 +0100, Jose Abreu wrote: > Currently we expect that clock driver produces the exact same value > as we are requiring. There can, and will, be some deviation however > so we need to take into account that instead of rejecting the mode. > > According to HDMI spec we have a max of +-0.5% for the pixel clock > frequency variation. Lets take that into an advantage and use it > to calculate how much deviation we can support. > > This patch was based on today's drm-misc-next. > > Signed-off-by: Jose Abreu <joabreu@synopsys.com> > Cc: Carlos Palminha <palminha@synopsys.com> > Cc: Alexey Brodkin <abrodkin@synopsys.com> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Dave Airlie <airlied@linux.ie> Finally our problem with EDID-less monitor is fixed with that patch. Thus, Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c index 611af74..20528ba 100644 --- a/drivers/gpu/drm/arc/arcpgu_crtc.c +++ b/drivers/gpu/drm/arc/arcpgu_crtc.c @@ -69,12 +69,13 @@ static enum drm_mode_status arc_pgu_crtc_mode_valid(struct drm_crtc *crtc, { struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc); long rate, clk_rate = mode->clock * 1000; + long diff = clk_rate / 200; /* +-0.5% allowed by HDMI spec*/ rate = clk_round_rate(arcpgu->clk, clk_rate); - if (rate != clk_rate) - return MODE_NOCLOCK; + if ((max(rate, clk_rate) - min(rate, clk_rate)) < diff) + return MODE_OK; - return MODE_OK; + return MODE_NOCLOCK; } static void arc_pgu_crtc_mode_set_nofb(struct drm_crtc *crtc)
Currently we expect that clock driver produces the exact same value as we are requiring. There can, and will, be some deviation however so we need to take into account that instead of rejecting the mode. According to HDMI spec we have a max of +-0.5% for the pixel clock frequency variation. Lets take that into an advantage and use it to calculate how much deviation we can support. This patch was based on today's drm-misc-next. Signed-off-by: Jose Abreu <joabreu@synopsys.com> Cc: Carlos Palminha <palminha@synopsys.com> Cc: Alexey Brodkin <abrodkin@synopsys.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@linux.ie> --- drivers/gpu/drm/arc/arcpgu_crtc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)