When ICSSG interfaces are brought down and brought up again, the
pru cores are shut down and booted again, flushing out all the memories
and start again in a clean state. Hence it is expected that the
IEP_CMP_CFG register needs to be flushed during iep_init() to ensure
that the existing residual configuration doesn't cause any unusual
behavior. If the register is not cleared, existing IEP_CMP_CFG set for
CMP1 will result in SYNC0_OUT signal based on the SYNC_OUT register values.

After bringing the interface up, calling PPS enable doesn't work as
the driver believes PPS is already enabled, (iep->pps_enabled is not
cleared during interface bring down) and driver will just return true
even though there is no signal. Fix this by disabling pps and perout.

Fixes: c1e0230eeaab ("net: ti: icss-iep: Add IEP driver")
Signed-off-by: Meghana Malladi <m-malladi@ti.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
---

Hi all,

This patch is based on net-next tagged next-20241205
v3: https://lore.kernel.org/all/20241205082831.777868-3-m-malladi@ti.com/

* Changes since v2 (v4-v2):
- Collected Reviewed-by tag from Roger Quadros <rogerq@kernel.org>

 drivers/net/ethernet/ti/icssg/icss_iep.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
index 5d6d1cf78e93..a96861debbe3 100644
--- a/drivers/net/ethernet/ti/icssg/icss_iep.c
+++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
@@ -215,6 +215,10 @@ static void icss_iep_enable_shadow_mode(struct icss_iep *iep)
 	for (cmp = IEP_MIN_CMP; cmp < IEP_MAX_CMP; cmp++) {
 		regmap_update_bits(iep->map, ICSS_IEP_CMP_STAT_REG,
 				   IEP_CMP_STATUS(cmp), IEP_CMP_STATUS(cmp));
+
+		regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
+				   IEP_CMP_CFG_CMP_EN(cmp), 0);
+
 	}
 
 	/* enable reset counter on CMP0 event */
@@ -780,6 +784,11 @@ int icss_iep_exit(struct icss_iep *iep)
 	}
 	icss_iep_disable(iep);
 
+	if (iep->pps_enabled)
+		icss_iep_pps_enable(iep, false);
+	else if (iep->perout_enabled)
+		icss_iep_perout_enable(iep, NULL, false);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(icss_iep_exit);
-- 
2.25.1

On Wed, Dec 11, 2024 at 07:29:41PM +0530, Meghana Malladi wrote:
>  drivers/net/ethernet/ti/icssg/icss_iep.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
> index 5d6d1cf78e93..a96861debbe3 100644
> --- a/drivers/net/ethernet/ti/icssg/icss_iep.c
> +++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
> @@ -215,6 +215,10 @@ static void icss_iep_enable_shadow_mode(struct icss_iep *iep)
>  	for (cmp = IEP_MIN_CMP; cmp < IEP_MAX_CMP; cmp++) {
>  		regmap_update_bits(iep->map, ICSS_IEP_CMP_STAT_REG,
>  				   IEP_CMP_STATUS(cmp), IEP_CMP_STATUS(cmp));
> +
> +		regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
> +				   IEP_CMP_CFG_CMP_EN(cmp), 0);
> +

Don't add this blank line.

You won't detect this by running checkpatch on the patch, but if you
apply the patch and re-run checkpatch on the file then it will complain
about this.

>  	}
>  
>  	/* enable reset counter on CMP0 event */
> @@ -780,6 +784,11 @@ int icss_iep_exit(struct icss_iep *iep)
>  	}
>  	icss_iep_disable(iep);
>  
> +	if (iep->pps_enabled)
> +		icss_iep_pps_enable(iep, false);
> +	else if (iep->perout_enabled)
> +		icss_iep_perout_enable(iep, NULL, false);


Do we need the else?  Could be written as:

	if (iep->pps_enabled)
		icss_iep_pps_enable(iep, false);
	if (iep->perout_enabled)
		icss_iep_perout_enable(iep, NULL, false);

regards,
dan carpenter

On 11/12/24 20:13, Dan Carpenter wrote:
> On Wed, Dec 11, 2024 at 07: 29: 41PM +0530, Meghana Malladi wrote: > 
> drivers/net/ethernet/ti/icssg/icss_iep. c | 9 +++++++++ > 1 file 
> changed, 9 insertions(+) > > diff --git 
> a/drivers/net/ethernet/ti/icssg/icss_iep. c 
> b/drivers/net/ethernet/ti/icssg/icss_iep. c
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> On Wed, Dec 11, 2024 at 07:29:41PM +0530, Meghana Malladi wrote:
>>  drivers/net/ethernet/ti/icssg/icss_iep.c | 9 +++++++++
>>  1 file changed, 9 insertions(+)
>> 
>> diff --git a/drivers/net/ethernet/ti/icssg/icss_iep.c b/drivers/net/ethernet/ti/icssg/icss_iep.c
>> index 5d6d1cf78e93..a96861debbe3 100644
>> --- a/drivers/net/ethernet/ti/icssg/icss_iep.c
>> +++ b/drivers/net/ethernet/ti/icssg/icss_iep.c
>> @@ -215,6 +215,10 @@ static void icss_iep_enable_shadow_mode(struct icss_iep *iep)
>>  	for (cmp = IEP_MIN_CMP; cmp < IEP_MAX_CMP; cmp++) {
>>  		regmap_update_bits(iep->map, ICSS_IEP_CMP_STAT_REG,
>>  				   IEP_CMP_STATUS(cmp), IEP_CMP_STATUS(cmp));
>> +
>> +		regmap_update_bits(iep->map, ICSS_IEP_CMP_CFG_REG,
>> +				   IEP_CMP_CFG_CMP_EN(cmp), 0);
>> +
> 
> Don't add this blank line.
> 
> You won't detect this by running checkpatch on the patch, but if you
> apply the patch and re-run checkpatch on the file then it will complain
> about this.
> 

I see, I will remove the blank line then.

>>  	}
>>  
>>  	/* enable reset counter on CMP0 event */
>> @@ -780,6 +784,11 @@ int icss_iep_exit(struct icss_iep *iep)
>>  	}
>>  	icss_iep_disable(iep);
>>  
>> +	if (iep->pps_enabled)
>> +		icss_iep_pps_enable(iep, false);
>> +	else if (iep->perout_enabled)
>> +		icss_iep_perout_enable(iep, NULL, false);
> 
> 
> Do we need the else?  Could be written as:
> 
> 	if (iep->pps_enabled)
> 		icss_iep_pps_enable(iep, false);
> 	if (iep->perout_enabled)
> 		icss_iep_perout_enable(iep, NULL, false);
> 

pps and perout and mutually exclusive, hence used if and else if.

> regards,
> dan carpenter
> 
>