2016-10-21 09:08:24

by Peter Griffin

Subject: [PATCH] ARM: sti: stih407-clocks: Identify critical clocks

Lots of platforms contain clocks which if turned off would prove fatal.
The only way to recover is to restart the board(s). This driver takes
references to clocks which are required to be always-on. The Common
Clk Framework will then take references to them. This way they will
not be turned off during the clk_disabled_unused() procedure.

In this patch we are identifying clocks, which if gated would render
the STiH407 development board unserviceable.

Signed-off-by: Peter Griffin <[email protected]>
---
arch/arm/boot/dts/stih407-clock.dtsi | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/stih407-clock.dtsi b/arch/arm/boot/dts/stih407-clock.dtsi
index 13029c0..34c119a 100644
--- a/arch/arm/boot/dts/stih407-clock.dtsi
+++ b/arch/arm/boot/dts/stih407-clock.dtsi
@@ -101,6 +101,7 @@
clocks = <&clk_sysin>;

clock-output-names = "clk-s-a0-pll-ofd-0";
+ clock-critical = <0>; /* clk-s-a0-pll-ofd-0 */
};

clk_s_a0_flexgen: clk-s-a0-flexgen {
@@ -112,6 +113,7 @@
<&clk_sysin>;

clock-output-names = "clk-ic-lmi0";
+ clock-critical = <CLK_IC_LMI0>;
};
};

@@ -126,6 +128,7 @@
"clk-s-c0-fs0-ch1",
"clk-s-c0-fs0-ch2",
"clk-s-c0-fs0-ch3";
+ clock-critical = <0>; /* clk-s-c0-fs0-ch0 */
};

clk_s_c0: clockgen-c@09103000 {
@@ -139,6 +142,7 @@
clocks = <&clk_sysin>;

clock-output-names = "clk-s-c0-pll0-odf-0";
+ clock-critical = <0>; /* clk-s-c0-pll0-odf-0 */
};

clk_s_c0_pll1: clk-s-c0-pll1 {
@@ -194,6 +198,12 @@
"clk-main-disp",
"clk-aux-disp",
"clk-compo-dvp";
+ clock-critical = <CLK_PROC_STFE>,
+ <CLK_ICN_CPU>,
+ <CLK_TX_ICN_DMU>,
+ <CLK_EXT2F_A9>,
+ <CLK_ICN_LMI>,
+ <CLK_ICN_SBC>;
};
};

--
1.9.1

2016-10-21 12:17:58

by Patrice CHOTARD

Subject: Re: [PATCH] ARM: sti: stih407-clocks: Identify critical clocks

On 10/21/2016 11:08 AM, Peter Griffin wrote:
> Lots of platforms contain clocks which if turned off would prove fatal.
> The only way to recover is to restart the board(s). This driver takes
> references to clocks which are required to be always-on. The Common
> Clk Framework will then take references to them. This way they will
> not be turned off during the clk_disabled_unused() procedure.
>
> In this patch we are identifying clocks, which if gated would render
> the STiH407 development board unserviceable.
>
> Signed-off-by: Peter Griffin <[email protected]>
> ---
> arch/arm/boot/dts/stih407-clock.dtsi | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/boot/dts/stih407-clock.dtsi b/arch/arm/boot/dts/stih407-clock.dtsi
> index 13029c0..34c119a 100644
> --- a/arch/arm/boot/dts/stih407-clock.dtsi
> +++ b/arch/arm/boot/dts/stih407-clock.dtsi
> @@ -101,6 +101,7 @@
> clocks = <&clk_sysin>;
>
> clock-output-names = "clk-s-a0-pll-ofd-0";
> + clock-critical = <0>; /* clk-s-a0-pll-ofd-0 */
> };
>
> clk_s_a0_flexgen: clk-s-a0-flexgen {
> @@ -112,6 +113,7 @@
> <&clk_sysin>;
>
> clock-output-names = "clk-ic-lmi0";
> + clock-critical = <CLK_IC_LMI0>;
> };
> };
>
> @@ -126,6 +128,7 @@
> "clk-s-c0-fs0-ch1",
> "clk-s-c0-fs0-ch2",
> "clk-s-c0-fs0-ch3";
> + clock-critical = <0>; /* clk-s-c0-fs0-ch0 */
> };
>
> clk_s_c0: clockgen-c@09103000 {
> @@ -139,6 +142,7 @@
> clocks = <&clk_sysin>;
>
> clock-output-names = "clk-s-c0-pll0-odf-0";
> + clock-critical = <0>; /* clk-s-c0-pll0-odf-0 */
> };
>
> clk_s_c0_pll1: clk-s-c0-pll1 {
> @@ -194,6 +198,12 @@
> "clk-main-disp",
> "clk-aux-disp",
> "clk-compo-dvp";
> + clock-critical = <CLK_PROC_STFE>,
> + <CLK_ICN_CPU>,
> + <CLK_TX_ICN_DMU>,
> + <CLK_EXT2F_A9>,
> + <CLK_ICN_LMI>,
> + <CLK_ICN_SBC>;
> };
> };
>
>

Acked-by: Patrice Chotard <[email protected]>

And applied !

Effectively, the job was done for STiH410 but i forgot to apply the same for STiH407

Thanks Peter ;-)