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* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
@ 2012-10-06 14:16 Liu Ying
  2012-10-06 18:00 ` Eric Nelson
  2012-10-19 23:58 ` Anatolij Gustschin
  0 siblings, 2 replies; 6+ messages in thread
From: Liu Ying @ 2012-10-06 14:16 UTC (permalink / raw)
  To: u-boot

From: Liu Ying <Ying.Liu@freescale.com>

This patch checks self-clear sw_ipu_rst bit in
SCR register of SRC controller to be cleared
after setting it to high to reset IPUv3. This
makes sure that IPUv3 finishes sofware reset.
A timeout mechanism is added to stop polling
on the bit status in case the bit could not be
cleared by the hardware automatically within
10 millisecond.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
---
 drivers/video/ipu_common.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
index 2020da9..fcc1745 100644
--- a/drivers/video/ipu_common.c
+++ b/drivers/video/ipu_common.c
@@ -94,6 +94,7 @@ struct ipu_ch_param {
 	temp1; \
 })
 
+#define IPU_SW_RST_TOUT_USEC	(10000)
 
 void clk_enable(struct clk *clk)
 {
@@ -392,11 +393,20 @@ void ipu_reset(void)
 {
 	u32 *reg;
 	u32 value;
+	int timeout = IPU_SW_RST_TOUT_USEC;
 
 	reg = (u32 *)SRC_BASE_ADDR;
 	value = __raw_readl(reg);
 	value = value | SW_IPU_RST;
 	__raw_writel(value, reg);
+
+	while (__raw_readl(reg) & SW_IPU_RST) {
+		udelay(1);
+		if (!(timeout--)) {
+			printf("ipu software reset timeout\n");
+			break;
+		}
+	};
 }
 
 /*
-- 
1.7.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
  2012-10-06 14:16 [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly Liu Ying
@ 2012-10-06 18:00 ` Eric Nelson
  2012-10-19 23:58 ` Anatolij Gustschin
  1 sibling, 0 replies; 6+ messages in thread
From: Eric Nelson @ 2012-10-06 18:00 UTC (permalink / raw)
  To: u-boot

Hi Liu Ying,

On 10/06/2012 07:16 AM, Liu Ying wrote:
> From: Liu Ying<Ying.Liu@freescale.com>
>
> This patch checks self-clear sw_ipu_rst bit in
> SCR register of SRC controller to be cleared
> after setting it to high to reset IPUv3. This
> makes sure that IPUv3 finishes sofware reset.
> A timeout mechanism is added to stop polling
> on the bit status in case the bit could not be
> cleared by the hardware automatically within
> 10 millisecond.
>
> Signed-off-by: Liu Ying<Ying.Liu@freescale.com>
> ---
>   drivers/video/ipu_common.c |   10 ++++++++++
>   1 files changed, 10 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
> index 2020da9..fcc1745 100644
> --- a/drivers/video/ipu_common.c
> +++ b/drivers/video/ipu_common.c
> @@ -94,6 +94,7 @@ struct ipu_ch_param {
>   	temp1; \
>   })
>
> +#define IPU_SW_RST_TOUT_USEC	(10000)
>
>   void clk_enable(struct clk *clk)
>   {
> @@ -392,11 +393,20 @@ void ipu_reset(void)
>   {
>   	u32 *reg;
>   	u32 value;
> +	int timeout = IPU_SW_RST_TOUT_USEC;
>
>   	reg = (u32 *)SRC_BASE_ADDR;
>   	value = __raw_readl(reg);
>   	value = value | SW_IPU_RST;
>   	__raw_writel(value, reg);
> +
> +	while (__raw_readl(reg)&  SW_IPU_RST) {
> +		udelay(1);
> +		if (!(timeout--)) {
> +			printf("ipu software reset timeout\n");
> +			break;
> +		}
> +	};
>   }
>
>   /*

Tested in the normal (successful) case on SABRE Lite.

Is there a situation under which this is known to fail or
is that a hypothetical?

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
  2012-10-06 14:16 [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly Liu Ying
  2012-10-06 18:00 ` Eric Nelson
@ 2012-10-19 23:58 ` Anatolij Gustschin
  1 sibling, 0 replies; 6+ messages in thread
From: Anatolij Gustschin @ 2012-10-19 23:58 UTC (permalink / raw)
  To: u-boot

Hi,
On Sat, 6 Oct 2012 22:16:04 +0800
Liu Ying <Ying.liu@freescale.com> wrote:

> From: Liu Ying <Ying.Liu@freescale.com>
> 
> This patch checks self-clear sw_ipu_rst bit in
> SCR register of SRC controller to be cleared
> after setting it to high to reset IPUv3. This
> makes sure that IPUv3 finishes sofware reset.
> A timeout mechanism is added to stop polling
> on the bit status in case the bit could not be
> cleared by the hardware automatically within
> 10 millisecond.
> 
> Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
> ---
>  drivers/video/ipu_common.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)

applied, thanks!

Anatolij

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
  2012-10-06 12:59 ` Fabio Estevam
@ 2012-10-06 12:59   ` Fabio Estevam
  0 siblings, 0 replies; 6+ messages in thread
From: Fabio Estevam @ 2012-10-06 12:59 UTC (permalink / raw)
  To: u-boot

On Sat, Oct 6, 2012 at 9:59 AM, Fabio Estevam <festevam@gmail.com> wrote:
> Hi Liu Ying,
>
> On Sat, Oct 6, 2012 at 7:32 AM, Liu Ying <Ying.liu@freescale.com> wrote:
>
>> @@ -397,6 +397,9 @@ void ipu_reset(void)
>>         value = __raw_readl(reg);
>>         value = value | SW_IPU_RST;
>>         __raw_writel(value, reg);
>> +
>> +       while (__raw_readl(reg) & SW_IPU_RST)
>> +               ;
>
> Ok, but if the reset fails we would hand the whole system.

I mean "hang"

>
> Wouldn't it be better to add a timeout here?
>
> Regards,
>
> Fabio Estevam

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
  2012-10-06 10:32 Liu Ying
@ 2012-10-06 12:59 ` Fabio Estevam
  2012-10-06 12:59   ` Fabio Estevam
  0 siblings, 1 reply; 6+ messages in thread
From: Fabio Estevam @ 2012-10-06 12:59 UTC (permalink / raw)
  To: u-boot

Hi Liu Ying,

On Sat, Oct 6, 2012 at 7:32 AM, Liu Ying <Ying.liu@freescale.com> wrote:

> @@ -397,6 +397,9 @@ void ipu_reset(void)
>         value = __raw_readl(reg);
>         value = value | SW_IPU_RST;
>         __raw_writel(value, reg);
> +
> +       while (__raw_readl(reg) & SW_IPU_RST)
> +               ;

Ok, but if the reset fails we would hand the whole system.

Wouldn't it be better to add a timeout here?

Regards,

Fabio Estevam

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly
@ 2012-10-06 10:32 Liu Ying
  2012-10-06 12:59 ` Fabio Estevam
  0 siblings, 1 reply; 6+ messages in thread
From: Liu Ying @ 2012-10-06 10:32 UTC (permalink / raw)
  To: u-boot

From: Liu Ying <Ying.Liu@freescale.com>

This patch checks self-clear sw_ipu_rst bit in
SCR register of SRC controller to be cleared
after setting it to high to reset IPUv3. This
makes sure that IPUv3 finishes sofware reset.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
---
 drivers/video/ipu_common.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c
index 2020da9..03b7382 100644
--- a/drivers/video/ipu_common.c
+++ b/drivers/video/ipu_common.c
@@ -397,6 +397,9 @@ void ipu_reset(void)
 	value = __raw_readl(reg);
 	value = value | SW_IPU_RST;
 	__raw_writel(value, reg);
+
+	while (__raw_readl(reg) & SW_IPU_RST)
+		;
 }
 
 /*
-- 
1.7.1

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-10-19 23:58 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-10-06 14:16 [U-Boot] [PATCH 1/1] ipu common: reset ipuv3 correctly Liu Ying
2012-10-06 18:00 ` Eric Nelson
2012-10-19 23:58 ` Anatolij Gustschin
  -- strict thread matches above, loose matches on Subject: below --
2012-10-06 10:32 Liu Ying
2012-10-06 12:59 ` Fabio Estevam
2012-10-06 12:59   ` Fabio Estevam

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