Re: [PATCH] clk: imx: Set CLK_SET_RATE_GATE for gate and divider clocks

Re: [PATCH] clk: imx: Set CLK_SET_RATE_GATE for gate and divider clocks

[Stephen Boyd]

Quoting Abel Vesa (2018-03-23 06:33:26)
> Add flag CLK_SET_RATE_GATE for i.MX gate and divider clocks on which the
> client drivers usually make clk_set_rate() call, so that the call will fa=
il
> when clock is still on instead of standing the risk of running into glitch
> issue. Rate cannot be changed when the clock is enabled due to the glitchy
> multiplexers.
> =

> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
> [initial patch from imx internal repo]
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> [carried over from 3.14 and also applied the flag to newer functions]

Is Shawn the author of this patch?

[PATCH v2] clk: imx: Set CLK_SET_RATE_GATE for gate and divider clocks

[Abel Vesa]

From: Shawn Guo <shawnguo@kernel.org>

Add flag CLK_SET_RATE_GATE for i.MX gate and divider clocks on which the
client drivers usually make clk_set_rate() call, so that the call will fail
when clock is still on instead of standing the risk of running into glitch
issue. Rate cannot be changed when the clock is enabled due to the glitchy
multiplexers.

Signed-off-by: Shawn Guo <shawnguo@kernel.org>
[initial patch from imx internal repo]
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
[carried over from 3.14 and also applied the flag to newer functions]
---

Changes since v1:
 - changed ownership as per initial patch

 drivers/clk/imx/clk.h | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
index 8076ec0..753ebc4 100644
--- a/drivers/clk/imx/clk.h
+++ b/drivers/clk/imx/clk.h
@@ -96,7 +96,8 @@ static inline struct clk *imx_clk_fixed_factor(const char *name,
 static inline struct clk *imx_clk_divider(const char *name, const char *parent,
 		void __iomem *reg, u8 shift, u8 width)
 {
-	return clk_register_divider(NULL, name, parent, CLK_SET_RATE_PARENT,
+	return clk_register_divider(NULL, name, parent,
+			CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
 			reg, shift, width, 0, &imx_ccm_lock);
 }
 
@@ -140,7 +141,8 @@ static inline struct clk *imx_clk_gate_dis(const char *name, const char *parent,
 static inline struct clk *imx_clk_gate2(const char *name, const char *parent,
 		void __iomem *reg, u8 shift)
 {
-	return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT, reg,
+	return clk_register_gate2(NULL, name, parent,
+			CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE, reg,
 			shift, 0x3, 0, &imx_ccm_lock, NULL);
 }
 
@@ -155,7 +157,8 @@ static inline struct clk *imx_clk_gate2_shared(const char *name,
 		const char *parent, void __iomem *reg, u8 shift,
 		unsigned int *share_count)
 {
-	return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT, reg,
+	return clk_register_gate2(NULL, name, parent,
+			CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE, reg,
 			shift, 0x3, 0, &imx_ccm_lock, share_count);
 }
 
@@ -164,8 +167,8 @@ static inline struct clk *imx_clk_gate2_shared2(const char *name,
 		unsigned int *share_count)
 {
 	return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT |
-				  CLK_OPS_PARENT_ENABLE, reg, shift, 0x3, 0,
-				  &imx_ccm_lock, share_count);
+			CLK_SET_RATE_GATE | CLK_OPS_PARENT_ENABLE,
+			reg, shift, 0x3, 0, &imx_ccm_lock, share_count);
 }
 
 static inline struct clk *imx_clk_gate2_cgr(const char *name,
@@ -187,7 +190,7 @@ static inline struct clk *imx_clk_gate4(const char *name, const char *parent,
 		void __iomem *reg, u8 shift)
 {
 	return clk_register_gate2(NULL, name, parent,
-			CLK_SET_RATE_PARENT | CLK_OPS_PARENT_ENABLE,
+		CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE | CLK_OPS_PARENT_ENABLE,
 			reg, shift, 0x3, 0, &imx_ccm_lock, NULL);
 }
 
-- 
2.7.4

Re: [PATCH v2] clk: imx: Set CLK_SET_RATE_GATE for gate and divider clocks

[Shawn Guo]

On Wed, Apr 11, 2018 at 05:03:29PM +0300, Abel Vesa wrote:
> From: Shawn Guo <shawnguo@kernel.org>
> 
> Add flag CLK_SET_RATE_GATE for i.MX gate and divider clocks on which the
> client drivers usually make clk_set_rate() call, so that the call will fail
> when clock is still on instead of standing the risk of running into glitch
> issue. Rate cannot be changed when the clock is enabled due to the glitchy
> multiplexers.
> 
> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
> [initial patch from imx internal repo]
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> [carried over from 3.14 and also applied the flag to newer functions]
> ---
> 
> Changes since v1:
>  - changed ownership as per initial patch

IIRC, the patch was created on vendor kernel long time ago to work
around a specific glitchy multiplexer issue seen on particular SoC.
I'm not sure it's good for the upstream kernel today.

Shawn

Re: [PATCH v2] clk: imx: Set CLK_SET_RATE_GATE for gate and divider clocks

[Stephen Boyd]

Quoting Shawn Guo (2018-04-17 19:32:16)
> On Wed, Apr 11, 2018 at 05:03:29PM +0300, Abel Vesa wrote:
> > From: Shawn Guo <shawnguo@kernel.org>
> > =

> > Add flag CLK_SET_RATE_GATE for i.MX gate and divider clocks on which the
> > client drivers usually make clk_set_rate() call, so that the call will =
fail
> > when clock is still on instead of standing the risk of running into gli=
tch
> > issue. Rate cannot be changed when the clock is enabled due to the glit=
chy
> > multiplexers.
> > =

> > Signed-off-by: Shawn Guo <shawnguo@kernel.org>
> > [initial patch from imx internal repo]
> > Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
> > [carried over from 3.14 and also applied the flag to newer functions]
> > ---
> > =

> > Changes since v1:
> >  - changed ownership as per initial patch
> =

> IIRC, the patch was created on vendor kernel long time ago to work
> around a specific glitchy multiplexer issue seen on particular SoC.
> I'm not sure it's good for the upstream kernel today.
> =


I'm taking this as a Nak. Resend or restart this discussion if you want
me to apply this.