[PATCH 0/3] clk: meson: fix mpll jitter

[PATCH 0/3] clk: meson: fix mpll jitter

[Jerome Brunet]

As reported on this [0] mpll series, We are observing a lot of jitter
on the MPLL outputs of the g12a. No such jitter is seen on gx family.
On the axg family, only MPLL2 seems affected.

The jitter can be as high as +/- 4%.

This is a problem for audio application. This may cause distortion on
i2s and completely break SPDIF.

After exchanging with Amlogic, it seems he have activated (by mistake)
the 'spread spectrum' feature.

This patchset properly set the bit responsible for the spread spectrum
in the mpll driver and add the required correction in the related clock
controllers.

Jerome Brunet (3):
  clk: meson: mpll: properly handle spread spectrum
  clk: meson: gxbb: no spread spectrum on mpll0
  clk: meson: axg: spread spectrum is on mpll2

 drivers/clk/meson/axg.c      | 10 +++++-----
 drivers/clk/meson/clk-mpll.c |  9 ++++++---
 drivers/clk/meson/clk-mpll.h |  1 +
 drivers/clk/meson/gxbb.c     |  5 -----
 4 files changed, 12 insertions(+), 13 deletions(-)

-- 
2.20.1

[PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Jerome Brunet]

The bit 'SSEN' available on some MPLL DSS outputs is not related to the
fractional part of the divider but to the function called
'Spread Spectrum'.

This function might be used to solve EM issues by adding a jitter on
clock signal. This widens the signal spectrum and weakens the peaks in it.

While spread spectrum might be useful for some application, it is
problematic for others, such as audio.

This patch introduce a new flag to the MPLL driver to enable (or not) the
spread spectrum function.

Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/clk/meson/clk-mpll.c | 9 ++++++---
 drivers/clk/meson/clk-mpll.h | 1 +
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
index 64d31c8ba3d0..2d39a8bc367c 100644
--- a/drivers/clk/meson/clk-mpll.c
+++ b/drivers/clk/meson/clk-mpll.c
@@ -141,9 +141,12 @@ static void mpll_init(struct clk_hw *hw)
 	/* Enable the fractional part */
 	meson_parm_write(clk->map, &mpll->sdm_en, 1);
 
-	/* Set additional fractional part enable if required */
-	if (MESON_PARM_APPLICABLE(&mpll->ssen))
-		meson_parm_write(clk->map, &mpll->ssen, 1);
+	/* Set spread spectrum if possible */
+	if (MESON_PARM_APPLICABLE(&mpll->ssen)) {
+		unsigned int ss =
+			mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0;
+		meson_parm_write(clk->map, &mpll->ssen, ss);
+	}
 
 	/* Set the magic misc bit if required */
 	if (MESON_PARM_APPLICABLE(&mpll->misc))
diff --git a/drivers/clk/meson/clk-mpll.h b/drivers/clk/meson/clk-mpll.h
index 2925fb939fdd..a991d568c43a 100644
--- a/drivers/clk/meson/clk-mpll.h
+++ b/drivers/clk/meson/clk-mpll.h
@@ -25,6 +25,7 @@ struct meson_clk_mpll_data {
 };
 
 #define CLK_MESON_MPLL_ROUND_CLOSEST	BIT(0)
+#define CLK_MESON_MPLL_SPREAD_SPECTRUM	BIT(1)
 
 extern const struct clk_ops meson_clk_mpll_ro_ops;
 extern const struct clk_ops meson_clk_mpll_ops;
-- 
2.20.1

[PATCH 2/3] clk: meson: gxbb: no spread spectrum on mpll0

[Jerome Brunet]

The documentation says there is an SSEN bit on mpll0 but, after testing
it, no spread spectrum function appears to be enabled by this bit on any
of the MPLLs.

Let's remove it until we know more

Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/clk/meson/gxbb.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/clk/meson/gxbb.c b/drivers/clk/meson/gxbb.c
index 04df2e208ed6..17d4e85bde65 100644
--- a/drivers/clk/meson/gxbb.c
+++ b/drivers/clk/meson/gxbb.c
@@ -679,11 +679,6 @@ static struct clk_regmap gxbb_mpll0_div = {
 			.shift   = 16,
 			.width   = 9,
 		},
-		.ssen = {
-			.reg_off = HHI_MPLL_CNTL,
-			.shift   = 25,
-			.width	 = 1,
-		},
 		.lock = &meson_clk_lock,
 	},
 	.hw.init = &(struct clk_init_data){
-- 
2.20.1

[PATCH 3/3] clk: meson: axg: spread spectrum is on mpll2

[Jerome Brunet]

After testing, it appears that the SSEN bit controls the spread
spectrum function on MPLL2, not MPLL0.

Fixes: 78b4af312f91 ("clk: meson-axg: add clock controller drivers")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/clk/meson/axg.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/meson/axg.c b/drivers/clk/meson/axg.c
index 7a8ef80e5f2c..3ddd0efc9ee0 100644
--- a/drivers/clk/meson/axg.c
+++ b/drivers/clk/meson/axg.c
@@ -469,11 +469,6 @@ static struct clk_regmap axg_mpll0_div = {
 			.shift   = 16,
 			.width   = 9,
 		},
-		.ssen = {
-			.reg_off = HHI_MPLL_CNTL,
-			.shift   = 25,
-			.width	 = 1,
-		},
 		.misc = {
 			.reg_off = HHI_PLL_TOP_MISC,
 			.shift   = 0,
@@ -568,6 +563,11 @@ static struct clk_regmap axg_mpll2_div = {
 			.shift   = 16,
 			.width   = 9,
 		},
+		.ssen = {
+			.reg_off = HHI_MPLL_CNTL,
+			.shift   = 25,
+			.width	 = 1,
+		},
 		.misc = {
 			.reg_off = HHI_PLL_TOP_MISC,
 			.shift   = 2,
-- 
2.20.1

Re: [PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Martin Blumenstingl]

Hi Jerome,

On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
> The bit 'SSEN' available on some MPLL DSS outputs is not related to the
> fractional part of the divider but to the function called
> 'Spread Spectrum'.
>
> This function might be used to solve EM issues by adding a jitter on
> clock signal. This widens the signal spectrum and weakens the peaks in it.
>
> While spread spectrum might be useful for some application, it is
> problematic for others, such as audio.
>
> This patch introduce a new flag to the MPLL driver to enable (or not) the
> spread spectrum function.
>
> Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> ---
>  drivers/clk/meson/clk-mpll.c | 9 ++++++---
>  drivers/clk/meson/clk-mpll.h | 1 +
>  2 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
> index 64d31c8ba3d0..2d39a8bc367c 100644
> --- a/drivers/clk/meson/clk-mpll.c
> +++ b/drivers/clk/meson/clk-mpll.c
> @@ -141,9 +141,12 @@ static void mpll_init(struct clk_hw *hw)
>         /* Enable the fractional part */
>         meson_parm_write(clk->map, &mpll->sdm_en, 1);
>
> -       /* Set additional fractional part enable if required */
> -       if (MESON_PARM_APPLICABLE(&mpll->ssen))
> -               meson_parm_write(clk->map, &mpll->ssen, 1);
> +       /* Set spread spectrum if possible */
> +       if (MESON_PARM_APPLICABLE(&mpll->ssen)) {
> +               unsigned int ss =
> +                       mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0;
> +               meson_parm_write(clk->map, &mpll->ssen, ss);
> +       }
this changes the "ssen" flag on all supported clocks from 1 (before
this patch) to 0 (after this patch).
is this on purpose and how does it affect existing clocks?

based on the original commit 1f737ffa13ef ("clk: meson: mpll: fix
mpll0 fractional part ignored") it seems that
CLK_MESON_MPLL_SPREAD_SPECTRUM should be set for mpll0 (at least on
GXBB and Meson8b)


Martin

Re: [PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Jerome Brunet]

On Fri, 2019-03-29 at 20:39 +0100, Martin Blumenstingl wrote:
> Hi Jerome,
> 
> On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > The bit 'SSEN' available on some MPLL DSS outputs is not related to the
> > fractional part of the divider but to the function called
> > 'Spread Spectrum'.
> > 
> > This function might be used to solve EM issues by adding a jitter on
> > clock signal. This widens the signal spectrum and weakens the peaks in it.
> > 
> > While spread spectrum might be useful for some application, it is
> > problematic for others, such as audio.
> > 
> > This patch introduce a new flag to the MPLL driver to enable (or not) the
> > spread spectrum function.
> > 
> > Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
> > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> > ---
> >  drivers/clk/meson/clk-mpll.c | 9 ++++++---
> >  drivers/clk/meson/clk-mpll.h | 1 +
> >  2 files changed, 7 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
> > index 64d31c8ba3d0..2d39a8bc367c 100644
> > --- a/drivers/clk/meson/clk-mpll.c
> > +++ b/drivers/clk/meson/clk-mpll.c
> > @@ -141,9 +141,12 @@ static void mpll_init(struct clk_hw *hw)
> >         /* Enable the fractional part */
> >         meson_parm_write(clk->map, &mpll->sdm_en, 1);
> > 
> > -       /* Set additional fractional part enable if required */
> > -       if (MESON_PARM_APPLICABLE(&mpll->ssen))
> > -               meson_parm_write(clk->map, &mpll->ssen, 1);
> > +       /* Set spread spectrum if possible */
> > +       if (MESON_PARM_APPLICABLE(&mpll->ssen)) {
> > +               unsigned int ss =
> > +                       mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0;
> > +               meson_parm_write(clk->map, &mpll->ssen, ss);
> > +       }
> this changes the "ssen" flag on all supported clocks from 1 (before
> this patch) to 0 (after this patch).
> is this on purpose and how does it affect existing clocks?

Yes, none of our application require spread spectrum

The fact is that only 2 MPLL had this bit, mpll0 on gx (without effect) and
mpll0 on axg: actually spread spectrum impacts mpll2, making it unusable, as
explained in the related patch

> 
> based on the original commit 1f737ffa13ef ("clk: meson: mpll: fix
> mpll0 fractional part ignored") it seems that
> CLK_MESON_MPLL_SPREAD_SPECTRUM should be set for mpll0 (at least on
> GXBB and Meson8b)
> 

There a patch specifically targeting gxbb.
I have checked on GXL and this bit had no effect (fractional part still on, no
spread spectrum)

So either we fixed something since then or I messed up when doing the patch
initially.

Feel free to cross check

> 
> Martin

Re: [PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Martin Blumenstingl]

Hi Jerome,

On Sat, Mar 30, 2019 at 12:07 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
> On Fri, 2019-03-29 at 20:39 +0100, Martin Blumenstingl wrote:
> > Hi Jerome,
> >
> > On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > > The bit 'SSEN' available on some MPLL DSS outputs is not related to the
> > > fractional part of the divider but to the function called
> > > 'Spread Spectrum'.
> > >
> > > This function might be used to solve EM issues by adding a jitter on
> > > clock signal. This widens the signal spectrum and weakens the peaks in it.
> > >
> > > While spread spectrum might be useful for some application, it is
> > > problematic for others, such as audio.
> > >
> > > This patch introduce a new flag to the MPLL driver to enable (or not) the
> > > spread spectrum function.
> > >
> > > Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
> > > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> > > ---
> > >  drivers/clk/meson/clk-mpll.c | 9 ++++++---
> > >  drivers/clk/meson/clk-mpll.h | 1 +
> > >  2 files changed, 7 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c
> > > index 64d31c8ba3d0..2d39a8bc367c 100644
> > > --- a/drivers/clk/meson/clk-mpll.c
> > > +++ b/drivers/clk/meson/clk-mpll.c
> > > @@ -141,9 +141,12 @@ static void mpll_init(struct clk_hw *hw)
> > >         /* Enable the fractional part */
> > >         meson_parm_write(clk->map, &mpll->sdm_en, 1);
> > >
> > > -       /* Set additional fractional part enable if required */
> > > -       if (MESON_PARM_APPLICABLE(&mpll->ssen))
> > > -               meson_parm_write(clk->map, &mpll->ssen, 1);
> > > +       /* Set spread spectrum if possible */
> > > +       if (MESON_PARM_APPLICABLE(&mpll->ssen)) {
> > > +               unsigned int ss =
> > > +                       mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0;
> > > +               meson_parm_write(clk->map, &mpll->ssen, ss);
> > > +       }
> > this changes the "ssen" flag on all supported clocks from 1 (before
> > this patch) to 0 (after this patch).
> > is this on purpose and how does it affect existing clocks?
>
> Yes, none of our application require spread spectrum
thank you for the explanation. can you please add it to the patch description?

> The fact is that only 2 MPLL had this bit, mpll0 on gx (without effect) and
> mpll0 on axg: actually spread spectrum impacts mpll2, making it unusable, as
> explained in the related patch
>
> >
> > based on the original commit 1f737ffa13ef ("clk: meson: mpll: fix
> > mpll0 fractional part ignored") it seems that
> > CLK_MESON_MPLL_SPREAD_SPECTRUM should be set for mpll0 (at least on
> > GXBB and Meson8b)
> >
>
> There a patch specifically targeting gxbb.
I missed that, sorry for the noise

> I have checked on GXL and this bit had no effect (fractional part still on, no
> spread spectrum)
>
> So either we fixed something since then or I messed up when doing the patch
> initially.
>
> Feel free to cross check
I tried it on Meson8b and it seems that there's no difference. I've
done a bit of software archaeology:
$ grep -R mpll_cntl uboot-2015-01-15-23a3562521/ | grep "=" | head -n3
uboot-2015-01-15-23a3562521/board/amlogic/m8_k100_1G/firmware/timming.c:
       .mpll_cntl = 0x600009A9,        //2.5G, fixed
uboot-2015-01-15-23a3562521/board/amlogic/m8_k100_2G/firmware/timming.c:
       .mpll_cntl = 0x600009A9,        //2.5G, fixed
uboot-2015-01-15-23a3562521/board/amlogic/m8b_ft_v1/firmware/timming.c:
.mpll_cntl = 0x600009A9,        //2.5G, fixed

Ethernet is still working on my Odroid-C1, so you can add my:
Tested-by: Martin Blumenstingl<martin.blumenstingl@googlemail.com>


Regards
Martin

Re: [PATCH 0/3] clk: meson: fix mpll jitter

[Martin Blumenstingl]

On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
> As reported on this [0] mpll series, We are observing a lot of jitter
> on the MPLL outputs of the g12a. No such jitter is seen on gx family.
> On the axg family, only MPLL2 seems affected.
>
> The jitter can be as high as +/- 4%.
>
> This is a problem for audio application. This may cause distortion on
> i2s and completely break SPDIF.
>
> After exchanging with Amlogic, it seems he have activated (by mistake)
> the 'spread spectrum' feature.
>
> This patchset properly set the bit responsible for the spread spectrum
> in the mpll driver and add the required correction in the related clock
> controllers.
>
> Jerome Brunet (3):
>   clk: meson: mpll: properly handle spread spectrum
this depends on a patch from your other series "clk: meson: fixup g12a
mpll": [0]
personally I would base the other series on this one because this one
contains a "Fixes" that (meaning that the patch will get backported
and that's easier if there aren't any conflicts)


Regards
Martin


[0] https://patchwork.kernel.org/patch/10868837/

Re: [PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Jerome Brunet]

On Sat, 2019-03-30 at 16:56 +0100, Martin Blumenstingl wrote:
> Hi Jerome,
> 
> On Sat, Mar 30, 2019 at 12:07 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > On Fri, 2019-03-29 at 20:39 +0100, Martin Blumenstingl wrote:
> > > Hi Jerome,
> > > 
> > > On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > > > The bit 'SSEN' available on some MPLL DSS outputs is not related to the
> > > > fractional part of the divider but to the function called
> > > > 'Spread Spectrum'.
> > > > 
> > > > This function might be used to solve EM issues by adding a jitter on
> > > > clock signal. This widens the signal spectrum and weakens the peaks in it.
> > > > 
> > > > While spread spectrum might be useful for some application, it is
> > > > problematic for others, such as audio.
> > > > 
> > > > This patch introduce a new flag to the MPLL driver to enable (or not) the
> > > > spread spectrum function.
> > > > 
> > > > Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
> > > > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> > > > ---
> > > >  drivers/clk/meson/clk-mpll.c | 9 ++++++---
> > > >  drivers/clk/meson/clk-mpll.h | 1 +
> > > >  2 files changed, 7 insertions(+), 3 deletions(-)
> > > > 

[...]

> > 
> > Yes, none of our application require spread spectrum
> thank you for the explanation. can you please add it to the patch description?

I think I described spread spectrum already in the commit description.

> 
> > The fact is that only 2 MPLL had this bit, mpll0 on gx (without effect) and
> > mpll0 on axg: actually spread spectrum impacts mpll2, making it unusable, as
> > explained in the related patch
> > 
> > > based on the original commit 1f737ffa13ef ("clk: meson: mpll: fix
> > > mpll0 fractional part ignored") it seems that
> > > CLK_MESON_MPLL_SPREAD_SPECTRUM should be set for mpll0 (at least on
> > > GXBB and Meson8b)
> > > 
> > 
> > There a patch specifically targeting gxbb.
> I missed that, sorry for the noise
> 
> > I have checked on GXL and this bit had no effect (fractional part still on, no
> > spread spectrum)
> > 
> > So either we fixed something since then or I messed up when doing the patch
> > initially.
> > 
> > Feel free to cross check
> I tried it on Meson8b and it seems that there's no difference. I've
> done a bit of software archaeology:
> $ grep -R mpll_cntl uboot-2015-01-15-23a3562521/ | grep "=" | head -n3
> uboot-2015-01-15-23a3562521/board/amlogic/m8_k100_1G/firmware/timming.c:
>        .mpll_cntl = 0x600009A9,        //2.5G, fixed
> uboot-2015-01-15-23a3562521/board/amlogic/m8_k100_2G/firmware/timming.c:
>        .mpll_cntl = 0x600009A9,        //2.5G, fixed
> uboot-2015-01-15-23a3562521/board/amlogic/m8b_ft_v1/firmware/timming.c:
> .mpll_cntl = 0x600009A9,        //2.5G, fixed
> 
> Ethernet is still working on my Odroid-C1, so you can add my:
> Tested-by: Martin Blumenstingl<martin.blumenstingl@googlemail.com>
> 
> 
> Regards
> Martin

Re: [PATCH 0/3] clk: meson: fix mpll jitter

[Jerome Brunet]

On Sat, 2019-03-30 at 16:58 +0100, Martin Blumenstingl wrote:
> On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > As reported on this [0] mpll series, We are observing a lot of jitter
> > on the MPLL outputs of the g12a. No such jitter is seen on gx family.
> > On the axg family, only MPLL2 seems affected.
> > 
> > The jitter can be as high as +/- 4%.
> > 
> > This is a problem for audio application. This may cause distortion on
> > i2s and completely break SPDIF.
> > 
> > After exchanging with Amlogic, it seems he have activated (by mistake)
> > the 'spread spectrum' feature.
> > 
> > This patchset properly set the bit responsible for the spread spectrum
> > in the mpll driver and add the required correction in the related clock
> > controllers.
> > 
> > Jerome Brunet (3):
> >   clk: meson: mpll: properly handle spread spectrum
> this depends on a patch from your other series "clk: meson: fixup g12a
> mpll": [0]
> personally I would base the other series on this one because this one
> contains a "Fixes" that (meaning that the patch will get backported
> and that's easier if there aren't any conflicts)

1) The other series [0] had been submitted before we knew about the fix which
is why this one is based on it.
2) Considering the amount of work that went through since the fixed commit, I
doubt it makes much of a difference.

I might do it if both series require a resend.

> 
> 
> Regards
> Martin
> 
> 
> [0] https://patchwork.kernel.org/patch/10868837/

Re: [PATCH 1/3] clk: meson: mpll: properly handle spread spectrum

[Martin Blumenstingl]

Hi Jerome,

On Mon, Apr 1, 2019 at 10:40 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
>
> On Sat, 2019-03-30 at 16:56 +0100, Martin Blumenstingl wrote:
> > Hi Jerome,
> >
> > On Sat, Mar 30, 2019 at 12:07 AM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > > On Fri, 2019-03-29 at 20:39 +0100, Martin Blumenstingl wrote:
> > > > Hi Jerome,
> > > >
> > > > On Fri, Mar 29, 2019 at 4:34 PM Jerome Brunet <jbrunet@baylibre.com> wrote:
> > > > > The bit 'SSEN' available on some MPLL DSS outputs is not related to the
> > > > > fractional part of the divider but to the function called
> > > > > 'Spread Spectrum'.
> > > > >
> > > > > This function might be used to solve EM issues by adding a jitter on
> > > > > clock signal. This widens the signal spectrum and weakens the peaks in it.
> > > > >
> > > > > While spread spectrum might be useful for some application, it is
> > > > > problematic for others, such as audio.
> > > > >
> > > > > This patch introduce a new flag to the MPLL driver to enable (or not) the
> > > > > spread spectrum function.
> > > > >
> > > > > Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored")
> > > > > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
> > > > > ---
> > > > >  drivers/clk/meson/clk-mpll.c | 9 ++++++---
> > > > >  drivers/clk/meson/clk-mpll.h | 1 +
> > > > >  2 files changed, 7 insertions(+), 3 deletions(-)
> > > > >
>
> [...]
>
> > >
> > > Yes, none of our application require spread spectrum
> > thank you for the explanation. can you please add it to the patch description?
>
> I think I described spread spectrum already in the commit description.
I haven't been clear about this one -  let me do it better this time:
if you have to re-send the patches can you please add a note stating
that "none of our application require spread spectrum" to the
description so it's clear that you're disabling spread spectrum on
purpose.
your explanation about spread spectrum itself is perfectly fine


Regards
Martin