diff options
Diffstat (limited to 'drivers/gpu/drm/rockchip')
| -rw-r--r-- | drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c index ba9e14da41b4..a25b98b7f5bd 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c @@ -1174,26 +1174,24 @@ static bool vop_crtc_mode_fixup(struct drm_crtc *crtc, * * Action plan: * - * 1. When DRM gives us a mode, we should add 999 Hz to it. That way - * if the clock we need is 60000001 Hz (~60 MHz) and DRM tells us to - * make 60000 kHz then the clock framework will actually give us - * the right clock. + * 1. Try to set the exact rate first, and confirm the clock framework + * can provide it. * - * NOTE: if the PLL (maybe through a divider) could actually make - * a clock rate 999 Hz higher instead of the one we want then this - * could be a problem. Unfortunately there's not much we can do - * since it's baked into DRM to use kHz. It shouldn't matter in - * practice since Rockchip PLLs are controlled by tables and - * even if there is a divider in the middle I wouldn't expect PLL - * rates in the table that are just a few kHz different. + * 2. If the clock framework cannot provide the exact rate, we should + * add 999 Hz to the requested rate. That way if the clock we need + * is 60000001 Hz (~60 MHz) and DRM tells us to make 60000 kHz then + * the clock framework will actually give us the right clock. * - * 2. Get the clock framework to round the rate for us to tell us + * 3. Get the clock framework to round the rate for us to tell us * what it will actually make. * - * 3. Store the rounded up rate so that we don't need to worry about + * 4. Store the rounded up rate so that we don't need to worry about * this in the actual clk_set_rate(). */ - rate = clk_round_rate(vop->dclk, adjusted_mode->clock * 1000 + 999); + rate = clk_round_rate(vop->dclk, adjusted_mode->clock * 1000); + if (rate / 1000 != adjusted_mode->clock) + rate = clk_round_rate(vop->dclk, + adjusted_mode->clock * 1000 + 999); adjusted_mode->clock = DIV_ROUND_UP(rate, 1000); return true; |