[PATCH] ARM: imx: cpuidle-imx6sx: Restrict the SW2ISO increase to i.MX6SX

[PATCH] ARM: imx: cpuidle-imx6sx: Restrict the SW2ISO increase to i.MX6SX

[Fabio Estevam]

Since commit 1e434b703248 ("ARM: imx: update the cpu power up timing
setting on i.mx6sx") some characters loss is noticed on i.MX6ULL UART
as reported by Christoph Niedermaier.

The intention of such commit was to increase the SW2ISO field for i.MX6SX
only, but since cpuidle-imx6sx is also used on i.MX6UL/i.MX6ULL this caused
unintended side effects on other SoCs.

Fix this problem by keeping the original SW2ISO value for i.MX6UL/i.MX6ULL
and only increase SW2ISO in the i.MX6SX case.

Cc: stable@vger.kernel.org
Fixes: 1e434b703248 ("ARM: imx: update the cpu power up timing setting on i.mx6sx")
Reported-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 arch/arm/mach-imx/cpuidle-imx6sx.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
index fd0053e47a15..57cb9c763222 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -15,6 +15,7 @@
 
 #include "common.h"
 #include "cpuidle.h"
+#include "hardware.h"
 
 static int imx6sx_idle_finish(unsigned long val)
 {
@@ -99,8 +100,12 @@ static struct cpuidle_driver imx6sx_cpuidle_driver = {
 	.safe_state_index = 0,
 };
 
+#define SW2ISO_ORIGINAL		0x2
+#define SW2ISO_IMX6SX		0xf
 int __init imx6sx_cpuidle_init(void)
 {
+	u32 sw2iso = SW2ISO_ORIGINAL;
+
 	imx6_set_int_mem_clk_lpm(true);
 	imx6_enable_rbc(false);
 	imx_gpc_set_l2_mem_power_in_lpm(false);
@@ -110,7 +115,9 @@ int __init imx6sx_cpuidle_init(void)
 	 * except for power up sw2iso which need to be
 	 * larger than LDO ramp up time.
 	 */
-	imx_gpc_set_arm_power_up_timing(0xf, 1);
+	if (cpu_is_imx6sx())
+		sw2iso = SW2ISO_IMX6SX;
+	imx_gpc_set_arm_power_up_timing(sw2iso, 1);
 	imx_gpc_set_arm_power_down_timing(1, 1);
 
 	return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
-- 
2.17.1


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Re: [PATCH] ARM: imx: cpuidle-imx6sx: Restrict the SW2ISO increase to i.MX6SX

[Sébastien Szymanski]

On 5/2/19 1:30 PM, Fabio Estevam wrote:
> Since commit 1e434b703248 ("ARM: imx: update the cpu power up timing
> setting on i.mx6sx") some characters loss is noticed on i.MX6ULL UART
> as reported by Christoph Niedermaier.
> 
> The intention of such commit was to increase the SW2ISO field for i.MX6SX
> only, but since cpuidle-imx6sx is also used on i.MX6UL/i.MX6ULL this caused
> unintended side effects on other SoCs.
> 
> Fix this problem by keeping the original SW2ISO value for i.MX6UL/i.MX6ULL
> and only increase SW2ISO in the i.MX6SX case.
> 
> Cc: stable@vger.kernel.org
> Fixes: 1e434b703248 ("ARM: imx: update the cpu power up timing setting on i.mx6sx")
> Reported-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
>  arch/arm/mach-imx/cpuidle-imx6sx.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
> index fd0053e47a15..57cb9c763222 100644
> --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> @@ -15,6 +15,7 @@
>  
>  #include "common.h"
>  #include "cpuidle.h"
> +#include "hardware.h"
>  
>  static int imx6sx_idle_finish(unsigned long val)
>  {
> @@ -99,8 +100,12 @@ static struct cpuidle_driver imx6sx_cpuidle_driver = {
>  	.safe_state_index = 0,
>  };
>  
> +#define SW2ISO_ORIGINAL		0x2
> +#define SW2ISO_IMX6SX		0xf
>  int __init imx6sx_cpuidle_init(void)
>  {
> +	u32 sw2iso = SW2ISO_ORIGINAL;
> +
>  	imx6_set_int_mem_clk_lpm(true);
>  	imx6_enable_rbc(false);
>  	imx_gpc_set_l2_mem_power_in_lpm(false);
> @@ -110,7 +115,9 @@ int __init imx6sx_cpuidle_init(void)
>  	 * except for power up sw2iso which need to be
>  	 * larger than LDO ramp up time.
>  	 */
> -	imx_gpc_set_arm_power_up_timing(0xf, 1);
> +	if (cpu_is_imx6sx())
> +		sw2iso = SW2ISO_IMX6SX;
> +	imx_gpc_set_arm_power_up_timing(sw2iso, 1);
>  	imx_gpc_set_arm_power_down_timing(1, 1);
>  
>  	return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
> 

Tested-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>

Regards,

-- 
Sébastien Szymanski
Software engineer, Armadeus Systems
Tel: +33 (0)9 72 29 41 44
Fax: +33 (0)9 72 28 79 26

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RE: [PATCH] ARM: imx: cpuidle-imx6sx: Restrict the SW2ISO increase to i.MX6SX [Klartext]

[Christoph Niedermaier]

From: Fabio Estevam <festevam@gmail.com>
Sent: Thursday 2nd May 2019 13:30
> Since commit 1e434b703248 ("ARM: imx: update the cpu power up timing
> setting on i.mx6sx") some characters loss is noticed on i.MX6ULL UART
> as reported by Christoph Niedermaier.
> 
> The intention of such commit was to increase the SW2ISO field for i.MX6SX
> only, but since cpuidle-imx6sx is also used on i.MX6UL/i.MX6ULL this caused
> unintended side effects on other SoCs.
> 
> Fix this problem by keeping the original SW2ISO value for i.MX6UL/i.MX6ULL
> and only increase SW2ISO in the i.MX6SX case.
> 
> Cc: stable@vger.kernel.org
> Fixes: 1e434b703248 ("ARM: imx: update the cpu power up timing setting on
> i.mx6sx")
> Reported-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
>  arch/arm/mach-imx/cpuidle-imx6sx.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
> index fd0053e47a15..57cb9c763222 100644
> --- a/arch/arm/mach-imx/cpuidle-imx6sx.c
> +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
> @@ -15,6 +15,7 @@
>  
>  #include "common.h"
>  #include "cpuidle.h"
> +#include "hardware.h"
>  
>  static int imx6sx_idle_finish(unsigned long val)
>  {
> @@ -99,8 +100,12 @@ static struct cpuidle_driver imx6sx_cpuidle_driver = {
>  .safe_state_index = 0,
>  };
>  
> +#define SW2ISO_ORIGINAL 0x2
> +#define SW2ISO_IMX6SX 0xf
>  int __init imx6sx_cpuidle_init(void)
>  {
> + u32 sw2iso = SW2ISO_ORIGINAL;
> +
>  imx6_set_int_mem_clk_lpm(true);
>  imx6_enable_rbc(false);
>  imx_gpc_set_l2_mem_power_in_lpm(false);
> @@ -110,7 +115,9 @@ int __init imx6sx_cpuidle_init(void)
>  * except for power up sw2iso which need to be
>  * larger than LDO ramp up time.
>  */
> - imx_gpc_set_arm_power_up_timing(0xf, 1);
> + if (cpu_is_imx6sx())
> + sw2iso = SW2ISO_IMX6SX;
> + imx_gpc_set_arm_power_up_timing(sw2iso, 1);
>  imx_gpc_set_arm_power_down_timing(1, 1);
>  
>  return cpuidle_register(&imx6sx_cpuidle_driver, NULL);
>

Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>

Best regards,

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