| Message ID | 20160614120044.30734-1-thierry.reding@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Tue, Jun 14, 2016 at 02:00:42PM +0200, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Enabling spread spectrum on pll_d2 can lead to issues with display > modes. HDMI monitors, for example, would report "Signal Error" and > some modes driven over DisplayPort would generate fuzzy horizontal > bands. > Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com> The only display clock we should enable spread spectrum for, is pll_dp. AFAIK the DP spec specifies the amount of spread which can be tolerated. Peter. > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > drivers/clk/tegra/clk-tegra210.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c > index 6bd1235d09b1..cd141a364c9d 100644 > --- a/drivers/clk/tegra/clk-tegra210.c > +++ b/drivers/clk/tegra/clk-tegra210.c > @@ -1914,8 +1914,9 @@ static struct tegra_clk_pll_params pll_d2_params = { > .sdm_din_mask = PLLA_SDM_DIN_MASK, > .sdm_ctrl_reg = PLLD2_MISC1, > .sdm_ctrl_en_mask = PLLD2_SDM_EN_MASK, > - .ssc_ctrl_reg = PLLD2_MISC1, > - .ssc_ctrl_en_mask = PLLD2_SSC_EN_MASK, > + /* disable spread-spectrum for pll_d2 */ > + .ssc_ctrl_reg = 0, > + .ssc_ctrl_en_mask = 0, > .round_p_to_pdiv = pll_qlin_p_to_pdiv, > .pdiv_tohw = pll_qlin_pdiv_to_hw, > .div_nmp = &pllss_nmp, > -- > 2.8.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/14/2016 8:00 AM, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Enabling spread spectrum on pll_d2 can lead to issues with display > modes. HDMI monitors, for example, would report "Signal Error" and > some modes driven over DisplayPort would generate fuzzy horizontal > bands. > > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > drivers/clk/tegra/clk-tegra210.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c > index 6bd1235d09b1..cd141a364c9d 100644 > --- a/drivers/clk/tegra/clk-tegra210.c > +++ b/drivers/clk/tegra/clk-tegra210.c > @@ -1914,8 +1914,9 @@ static struct tegra_clk_pll_params pll_d2_params = { > .sdm_din_mask = PLLA_SDM_DIN_MASK, > .sdm_ctrl_reg = PLLD2_MISC1, > .sdm_ctrl_en_mask = PLLD2_SDM_EN_MASK, > - .ssc_ctrl_reg = PLLD2_MISC1, > - .ssc_ctrl_en_mask = PLLD2_SSC_EN_MASK, > + /* disable spread-spectrum for pll_d2 */ > + .ssc_ctrl_reg = 0, > + .ssc_ctrl_en_mask = 0, > .round_p_to_pdiv = pll_qlin_p_to_pdiv, > .pdiv_tohw = pll_qlin_pdiv_to_hw, > .div_nmp = &pllss_nmp, > Acked-by: Rhyland Klein <rklein@nvidia.com>
diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c index 6bd1235d09b1..cd141a364c9d 100644 --- a/drivers/clk/tegra/clk-tegra210.c +++ b/drivers/clk/tegra/clk-tegra210.c @@ -1914,8 +1914,9 @@ static struct tegra_clk_pll_params pll_d2_params = { .sdm_din_mask = PLLA_SDM_DIN_MASK, .sdm_ctrl_reg = PLLD2_MISC1, .sdm_ctrl_en_mask = PLLD2_SDM_EN_MASK, - .ssc_ctrl_reg = PLLD2_MISC1, - .ssc_ctrl_en_mask = PLLD2_SSC_EN_MASK, + /* disable spread-spectrum for pll_d2 */ + .ssc_ctrl_reg = 0, + .ssc_ctrl_en_mask = 0, .round_p_to_pdiv = pll_qlin_p_to_pdiv, .pdiv_tohw = pll_qlin_pdiv_to_hw, .div_nmp = &pllss_nmp,