Hi, On Wed, Jan 26, 2022 at 6:58 AM Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > From: Douglas Anderson <dianders@xxxxxxxxxxxx> > > Jitter was improved by lowering the MPLL bandwidth to account for high > frequency noise in the rk3288 PLL. In each case MPLL bandwidth was > lowered only enough to get us a comfortable margin. We believe that > lowering the bandwidth like this is safe given sufficient testing. > > Changes since v3: > - new patch > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx> > (am from https://patchwork.kernel.org/patch/9223301/) Probably remove the "am from" line? It's not standard in upstream and that link doesn't seem to go anywhere anymore... > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> > --- > drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 16 ++-------------- > 1 file changed, 2 insertions(+), 14 deletions(-) > > diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c > index c44eb4d2e2d5..77f82a4fd027 100644 > --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c > +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c > @@ -176,20 +176,8 @@ static const struct dw_hdmi_mpll_config rockchip_mpll_cfg[] = { > static const struct dw_hdmi_curr_ctrl rockchip_cur_ctr[] = { > /* pixelclk bpp8 bpp10 bpp12 */ > { > - 40000000, { 0x0018, 0x0018, 0x0018 }, > - }, { > - 65000000, { 0x0028, 0x0028, 0x0028 }, > - }, { > - 66000000, { 0x0038, 0x0038, 0x0038 }, > - }, { > - 74250000, { 0x0028, 0x0038, 0x0038 }, > - }, { > - 83500000, { 0x0028, 0x0038, 0x0038 }, > - }, { > - 146250000, { 0x0038, 0x0038, 0x0038 }, > - }, { > - 148500000, { 0x0000, 0x0038, 0x0038 }, > - }, { > + 600000000, { 0x0000, 0x0000, 0x0000 }, > + }, { This is what we did for rk3288. I can't personally vouch for the effects on other SoCs. -Doug
