[PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[SZ Lin (林上智)]

According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register is only
available when PHY is configured in RGMII mode with 10Mbps speed. It will
cause some networking issues without RGMII mode, such as carrier sense
errors and low throughput. TI also mentioned this issue in their forum[4].

This patch adds the check mechanism for PHY interface with RGMII interface
type, the in-band mode can only be set in RGMII mode with 10Mbps speed.

References:
[1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
[2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
[3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
[4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155

Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
Signed-off-by: Schuyler Patton <spatton@ti.com>
---
Changes from v1:
- Use phy_interface_is_rgmii helper function
- Remove blank line

 drivers/net/ethernet/ti/cpsw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 1b1b78fdc138..b2b30c9df037 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -1014,7 +1014,8 @@ static void _cpsw_adjust_link(struct cpsw_slave *slave,
 		/* set speed_in input in case RMII mode is used in 100Mbps */
 		if (phy->speed == 100)
 			mac_control |= BIT(15);
-		else if (phy->speed == 10)
+		/* in band mode only works in 10Mbps RGMII mode */
+		else if ((phy->speed == 10) && phy_interface_is_rgmii(phy))
 			mac_control |= BIT(18); /* In Band mode */
 
 		if (priv->rx_pause)
-- 
2.16.2

Re: [PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[Grygorii Strashko]

On 03/15/2018 11:56 AM, SZ Lin (林上智) wrote:
> According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
> DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register is only
> available when PHY is configured in RGMII mode with 10Mbps speed. It will
> cause some networking issues without RGMII mode, such as carrier sense
> errors and low throughput. TI also mentioned this issue in their forum[4].
> 
> This patch adds the check mechanism for PHY interface with RGMII interface
> type, the in-band mode can only be set in RGMII mode with 10Mbps speed.
> 
> References:
> [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
> [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
> [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
> [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155
> 
> Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
> Signed-off-by: Schuyler Patton <spatton@ti.com>
> ---
> Changes from v1:
> - Use phy_interface_is_rgmii helper function
> - Remove blank line
> 

Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>

>   drivers/net/ethernet/ti/cpsw.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> index 1b1b78fdc138..b2b30c9df037 100644
> --- a/drivers/net/ethernet/ti/cpsw.c
> +++ b/drivers/net/ethernet/ti/cpsw.c
> @@ -1014,7 +1014,8 @@ static void _cpsw_adjust_link(struct cpsw_slave *slave,
>   		/* set speed_in input in case RMII mode is used in 100Mbps */
>   		if (phy->speed == 100)
>   			mac_control |= BIT(15);
> -		else if (phy->speed == 10)
> +		/* in band mode only works in 10Mbps RGMII mode */
> +		else if ((phy->speed == 10) && phy_interface_is_rgmii(phy))
>   			mac_control |= BIT(18); /* In Band mode */
>   
>   		if (priv->rx_pause)
> 

-- 
regards,
-grygorii

Re: [PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[Grygorii Strashko]

On 03/15/2018 12:39 PM, Grygorii Strashko wrote:
> 
> 
> On 03/15/2018 11:56 AM, SZ Lin (林上智) wrote:
>> According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
>> DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register is 
>> only
>> available when PHY is configured in RGMII mode with 10Mbps speed. It will
>> cause some networking issues without RGMII mode, such as carrier sense
>> errors and low throughput. TI also mentioned this issue in their 
>> forum[4].
>>
>> This patch adds the check mechanism for PHY interface with RGMII 
>> interface
>> type, the in-band mode can only be set in RGMII mode with 10Mbps speed.
>>
>> References:
>> [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
>> [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
>> [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
>> [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155
>>
>> Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
>> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
>> Signed-off-by: Schuyler Patton <spatton@ti.com>
>> ---
>> Changes from v1:
>> - Use phy_interface_is_rgmii helper function
>> - Remove blank line
>>
> 
> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
> 

Also could this be marked as stable material 4.9+?

-- 
regards,
-grygorii

Re: [PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[Florian Fainelli]

On 03/15/2018 11:18 AM, Grygorii Strashko wrote:
> 
> 
> On 03/15/2018 12:39 PM, Grygorii Strashko wrote:
>>
>>
>> On 03/15/2018 11:56 AM, SZ Lin (林上智) wrote:
>>> According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
>>> DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register
>>> is only
>>> available when PHY is configured in RGMII mode with 10Mbps speed. It
>>> will
>>> cause some networking issues without RGMII mode, such as carrier sense
>>> errors and low throughput. TI also mentioned this issue in their
>>> forum[4].
>>>
>>> This patch adds the check mechanism for PHY interface with RGMII
>>> interface
>>> type, the in-band mode can only be set in RGMII mode with 10Mbps speed.
>>>
>>> References:
>>> [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
>>> [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
>>> [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
>>> [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155
>>>
>>> Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
>>> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
>>> Signed-off-by: Schuyler Patton <spatton@ti.com>
>>> ---
>>> Changes from v1:
>>> - Use phy_interface_is_rgmii helper function
>>> - Remove blank line
>>>
>>
>> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>
> 
> Also could this be marked as stable material 4.9+?

This is not how it works for networking changes, just make sure you
provide a "Fixes:" tag, and David would usually take care of queueing
the change to -stable accordingly:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/netdev-FAQ.txt#n148
-- 
Florian

Re: [PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[Grygorii Strashko]

On 03/15/2018 01:29 PM, Florian Fainelli wrote:
> On 03/15/2018 11:18 AM, Grygorii Strashko wrote:
>>
>>
>> On 03/15/2018 12:39 PM, Grygorii Strashko wrote:
>>>
>>>
>>> On 03/15/2018 11:56 AM, SZ Lin (林上智) wrote:
>>>> According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
>>>> DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register
>>>> is only
>>>> available when PHY is configured in RGMII mode with 10Mbps speed. It
>>>> will
>>>> cause some networking issues without RGMII mode, such as carrier sense
>>>> errors and low throughput. TI also mentioned this issue in their
>>>> forum[4].
>>>>
>>>> This patch adds the check mechanism for PHY interface with RGMII
>>>> interface
>>>> type, the in-band mode can only be set in RGMII mode with 10Mbps speed.
>>>>
>>>> References:
>>>> [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
>>>> [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
>>>> [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
>>>> [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155
>>>>
>>>> Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
>>>> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
>>>> Signed-off-by: Schuyler Patton <spatton@ti.com>
>>>> ---
>>>> Changes from v1:
>>>> - Use phy_interface_is_rgmii helper function
>>>> - Remove blank line
>>>>
>>>
>>> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>>
>>
>> Also could this be marked as stable material 4.9+?
> 
> This is not how it works for networking changes, just make sure you
> provide a "Fixes:" tag, and David would usually take care of queueing
> the change to -stable accordingly:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/networking/netdev-FAQ.txt#n148
> 

Sry, I know that, but this patch fixes very old commit [1] and it can't be
applied to old Kernels without merge conflicts or build errors:(, 
so I've manually checked if it can be applied to most recent stable kernels
and noted kernel versions here.
Also there is dependency from phy_interface_is_rgmii() which was merged in v4.2.

[1] commit a81d8762d713 ("drivers: net cpsw: Enable In Band mode in cpsw for 10 mbps")
^ went in v3.13
-- 
regards,
-grygorii

Re: [PATCH v2] net: ethernet: ti: cpsw: add check for in-band mode setting with RGMII PHY interface

[David Miller]

From: SZ Lin (林上智) <sz.lin@moxa.com>
Date: Fri, 16 Mar 2018 00:56:01 +0800

> According to AM335x TRM[1] 14.3.6.2, AM437x TRM[2] 15.3.6.2 and
> DRA7 TRM[3] 24.11.4.8.7.3.3, in-band mode in EXT_EN(bit18) register is only
> available when PHY is configured in RGMII mode with 10Mbps speed. It will
> cause some networking issues without RGMII mode, such as carrier sense
> errors and low throughput. TI also mentioned this issue in their forum[4].
> 
> This patch adds the check mechanism for PHY interface with RGMII interface
> type, the in-band mode can only be set in RGMII mode with 10Mbps speed.
> 
> References:
> [1]: https://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
> [2]: http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf
> [3]: http://www.ti.com/lit/ug/spruic2b/spruic2b.pdf
> [4]: https://e2e.ti.com/support/arm/sitara_arm/f/791/p/640765/2392155
> 
> Suggested-by: Holsety Chen (陳憲輝) <Holsety.Chen@moxa.com>
> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
> Signed-off-by: Schuyler Patton <spatton@ti.com>

Applied and queued up for -stable, thank you.