Re: [PATCH V6 8/8] drm/mediatek: fix the rate of parent for hdmi phy in MT2701

CK Hu
2019-03-21T05:32:57Z

Hi, Wangyan:

On Wed, 2019-03-06 at 18:13 +0800, CK Hu wrote:
> Hi, Wangyan:
>
> On Mon, 2019-02-25 at 10:09 +0800, wangyan wang wrote:
> > From: chunhui dai <chunhui.dai@mediatek.com>
> >
> > We should not change the rate of parent for hdmi phy when
> > doing round_rate for this clock. The parent clock of hdmi
> > phy must be the same as it. We change it when doing set_rate
> > only.
> >
> > Signed-off-by: chunhui dai <chunhui.dai@mediatek.com>
> > Signed-off-by: wangyan wang <wangyan.wang@mediatek.com>
> > ---
> > drivers/gpu/drm/mediatek/mtk_hdmi_phy.c | 14 --------------
> > drivers/gpu/drm/mediatek/mtk_hdmi_phy.h | 3 ---
> > drivers/gpu/drm/mediatek/mtk_mt2701_hdmi_phy.c | 11 +++++++++++
> > drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c | 14 ++++++++++++++
> > 4 files changed, 25 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_phy.c b/drivers/gpu/drm/mediatek/mtk_hdmi_phy.c
> > index 370309d684ec..ca8bc1489f37 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_hdmi_phy.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_phy.c
> > @@ -15,20 +15,6 @@ static const struct phy_ops mtk_hdmi_phy_dev_ops = {
> > .owner = THIS_MODULE,
> > };
> >
> > -long mtk_hdmi_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> > - unsigned long *parent_rate)
> > -{
> > - struct mtk_hdmi_phy *hdmi_phy = to_mtk_hdmi_phy(hw);
> > -
> > - hdmi_phy->pll_rate = rate;
> > - if (rate <= 74250000)
> > - *parent_rate = rate;
> > - else
> > - *parent_rate = rate / 2;
> > -
> > - return rate;
> > -}
> > -
> > u32 mtk_hdmi_phy_read(struct mtk_hdmi_phy *hdmi_phy, u32 offset)
> > {
> > return readl(hdmi_phy->regs + offset);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_phy.h b/drivers/gpu/drm/mediatek/mtk_hdmi_phy.h
> > index 446e2acd1926..c6061ad15ff0 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_hdmi_phy.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_phy.h
> > @@ -50,9 +50,6 @@ void mtk_hdmi_phy_set_bits(struct mtk_hdmi_phy *hdmi_phy, u32 offset,
> > void mtk_hdmi_phy_mask(struct mtk_hdmi_phy *hdmi_phy, u32 offset,
> > u32 val, u32 mask);
> > struct mtk_hdmi_phy *to_mtk_hdmi_phy(struct clk_hw *hw);
> > -long mtk_hdmi_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> > - unsigned long *parent_rate);
> > -
> > extern struct platform_driver mtk_hdmi_phy_driver;
> > extern struct mtk_hdmi_phy_conf mtk_hdmi_phy_8173_conf;
> > extern struct mtk_hdmi_phy_conf mtk_hdmi_phy_2701_conf;
> > diff --git a/drivers/gpu/drm/mediatek/mtk_mt2701_hdmi_phy.c b/drivers/gpu/drm/mediatek/mtk_mt2701_hdmi_phy.c
> > index 88dd9e812ca0..33893a180c2e 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_mt2701_hdmi_phy.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_mt2701_hdmi_phy.c
> > @@ -152,6 +152,17 @@ static int mtk_hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> > RG_HDMITX_DRV_IBIAS_MASK);
> > return 0;
> > }
> > +
> > +static long mtk_hdmi_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long *parent_rate)
> > +{
> > + struct mtk_hdmi_phy *hdmi_phy = to_mtk_hdmi_phy(hw);
> > +
> > + hdmi_phy->pll_rate = rate;
>
> I think you don't need to save the rate into pll_rate here, pll_rate
> would be set in set_rate() or recalc_rate().

As offline discuss, you mention that this function just need to return
current rate. I think you could just remove this line
'hdmi_phy->pll_rate = rate;' and return rate only. You don't need to
assign hdmi_phy->pll_rate here because it would be set later in
set_rate().

Regards,
CK

>
> Regards,
> CK
>
> > +
> > + return rate;
> > +}
> > +
> > static unsigned long mtk_hdmi_pll_recalc_rate(struct clk_hw *hw,
> > unsigned long parent_rate)
> > {
> > diff --git a/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c b/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > index 63dde42521b8..3a339f516613 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_mt8173_hdmi_phy.c
> > @@ -285,6 +285,20 @@ static int mtk_hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> > return 0;
> > }
> >
> > +static long mtk_hdmi_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> > + unsigned long *parent_rate)
> > +{
> > + struct mtk_hdmi_phy *hdmi_phy = to_mtk_hdmi_phy(hw);
> > +
> > + hdmi_phy->pll_rate = rate;
> > + if (rate <= 74250000)
> > + *parent_rate = rate;
> > + else
> > + *parent_rate = rate / 2;
> > +
> > + return rate;
> > +}
> > +
> > static unsigned long mtk_hdmi_pll_recalc_rate(struct clk_hw *hw,
> > unsigned long parent_rate)
> > {
>