[PATCH v2] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[PATCH v2] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[Siddharth Vadapalli]

Commit b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in
wiz driver") added support for USXGMII mode. In doing so, P0_REFCLK_SEL
was set to "pcs_mac_clk_divx1_ln_0" (0x3) and P0_STANDARD_MODE was set to
LANE_MODE_GEN1, which results in a data rate of 5.15625 Gbps. However,
since the USXGMII mode can support up to 10.3125 Gbps data rate, the
aforementioned fields should be set to "pcs_mac_clk_divx0_ln_0" (0x2) and
LANE_MODE_GEN2 respectively. Fix the configuration accordingly to truly
support USXGMII up to 10G.

Fixes: b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in wiz driver")
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
---

Hello,

This patch is based on commit
9852d85ec9d4 Linux 6.12-rc1
of mainline Linux.

v1:
https://lore.kernel.org/r/20240910091714.1082191-1-s-vadapalli@ti.com/
Changes since v1:
- Rebased to Linux 6.12-rc1.

Regards,
Siddharth.

 drivers/phy/ti/phy-j721e-wiz.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
index a6c0c5607ffd..c6e846d385d2 100644
--- a/drivers/phy/ti/phy-j721e-wiz.c
+++ b/drivers/phy/ti/phy-j721e-wiz.c
@@ -450,8 +450,8 @@ static int wiz_mode_select(struct wiz *wiz)
 		} else if (wiz->lane_phy_type[i] == PHY_TYPE_USXGMII) {
 			ret = regmap_field_write(wiz->p0_mac_src_sel[i], 0x3);
 			ret = regmap_field_write(wiz->p0_rxfclk_sel[i], 0x3);
-			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x3);
-			mode = LANE_MODE_GEN1;
+			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x2);
+			mode = LANE_MODE_GEN2;
 		} else {
 			continue;
 		}
-- 
2.40.1


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Re: [PATCH v2] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[Roger Quadros]

Hi Siddharth,

On 30/09/2024 12:57, Siddharth Vadapalli wrote:
> Commit b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in
> wiz driver") added support for USXGMII mode. In doing so, P0_REFCLK_SEL
> was set to "pcs_mac_clk_divx1_ln_0" (0x3) and P0_STANDARD_MODE was set to
> LANE_MODE_GEN1, which results in a data rate of 5.15625 Gbps. However,
> since the USXGMII mode can support up to 10.3125 Gbps data rate, the
> aforementioned fields should be set to "pcs_mac_clk_divx0_ln_0" (0x2) and
> LANE_MODE_GEN2 respectively. Fix the configuration accordingly to truly
> support USXGMII up to 10G.
> 
> Fixes: b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in wiz driver")
> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> ---
> 
> Hello,
> 
> This patch is based on commit
> 9852d85ec9d4 Linux 6.12-rc1
> of mainline Linux.
> 
> v1:
> https://lore.kernel.org/r/20240910091714.1082191-1-s-vadapalli@ti.com/
> Changes since v1:
> - Rebased to Linux 6.12-rc1.
> 
> Regards,
> Siddharth.
> 
>  drivers/phy/ti/phy-j721e-wiz.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
> index a6c0c5607ffd..c6e846d385d2 100644
> --- a/drivers/phy/ti/phy-j721e-wiz.c
> +++ b/drivers/phy/ti/phy-j721e-wiz.c
> @@ -450,8 +450,8 @@ static int wiz_mode_select(struct wiz *wiz)
>  		} else if (wiz->lane_phy_type[i] == PHY_TYPE_USXGMII) {
>  			ret = regmap_field_write(wiz->p0_mac_src_sel[i], 0x3);
>  			ret = regmap_field_write(wiz->p0_rxfclk_sel[i], 0x3);

I'm not sure. Don't we have to change rxfclk as well?

> -			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x3);
> -			mode = LANE_MODE_GEN1;
> +			ret = regmap_field_write(wiz->p0_refclk_sel[i], 0x2);
> +			mode = LANE_MODE_GEN2;
>  		} else {
>  			continue;
>  		}

-- 
cheers,
-roger

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Re: [PATCH v2] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[Siddharth Vadapalli]

On Mon, Sep 30, 2024 at 05:06:35PM +0300, Roger Quadros wrote:

Hello Roger,

> Hi Siddharth,
> 
> On 30/09/2024 12:57, Siddharth Vadapalli wrote:
> > Commit b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in
> > wiz driver") added support for USXGMII mode. In doing so, P0_REFCLK_SEL
> > was set to "pcs_mac_clk_divx1_ln_0" (0x3) and P0_STANDARD_MODE was set to
> > LANE_MODE_GEN1, which results in a data rate of 5.15625 Gbps. However,
> > since the USXGMII mode can support up to 10.3125 Gbps data rate, the
> > aforementioned fields should be set to "pcs_mac_clk_divx0_ln_0" (0x2) and
> > LANE_MODE_GEN2 respectively. Fix the configuration accordingly to truly
> > support USXGMII up to 10G.
> > 
> > Fixes: b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in wiz driver")
> > Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>

[...]

> > diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
> > index a6c0c5607ffd..c6e846d385d2 100644
> > --- a/drivers/phy/ti/phy-j721e-wiz.c
> > +++ b/drivers/phy/ti/phy-j721e-wiz.c
> > @@ -450,8 +450,8 @@ static int wiz_mode_select(struct wiz *wiz)
> >  		} else if (wiz->lane_phy_type[i] == PHY_TYPE_USXGMII) {
> >  			ret = regmap_field_write(wiz->p0_mac_src_sel[i], 0x3);
> >  			ret = regmap_field_write(wiz->p0_rxfclk_sel[i], 0x3);
> 
> I'm not sure. Don't we have to change rxfclk as well?

This patch was validated on a custom board with the J7200 SR 2.0 SoC.
The signal corresponding to the USXGMII lane of the SERDES was measured
to be 5 Gbps without this patch and 10 Gbps with this patch applied,
with no other changes required. Apart from measuring the signal, ping
was also validated.

Regards,
Siddharth.

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Re: [PATCH v2] phy: ti: phy-j721e-wiz: fix usxgmii configuration

[Roger Quadros]

On 01/10/2024 06:10, Siddharth Vadapalli wrote:
> On Mon, Sep 30, 2024 at 05:06:35PM +0300, Roger Quadros wrote:
> 
> Hello Roger,
> 
>> Hi Siddharth,
>>
>> On 30/09/2024 12:57, Siddharth Vadapalli wrote:
>>> Commit b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in
>>> wiz driver") added support for USXGMII mode. In doing so, P0_REFCLK_SEL
>>> was set to "pcs_mac_clk_divx1_ln_0" (0x3) and P0_STANDARD_MODE was set to
>>> LANE_MODE_GEN1, which results in a data rate of 5.15625 Gbps. However,
>>> since the USXGMII mode can support up to 10.3125 Gbps data rate, the
>>> aforementioned fields should be set to "pcs_mac_clk_divx0_ln_0" (0x2) and
>>> LANE_MODE_GEN2 respectively. Fix the configuration accordingly to truly
>>> support USXGMII up to 10G.
>>>
>>> Fixes: b64a85fb8f53 ("phy: ti: phy-j721e-wiz.c: Add usxgmii support in wiz driver")
>>> Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
> 
> [...]
> 
>>> diff --git a/drivers/phy/ti/phy-j721e-wiz.c b/drivers/phy/ti/phy-j721e-wiz.c
>>> index a6c0c5607ffd..c6e846d385d2 100644
>>> --- a/drivers/phy/ti/phy-j721e-wiz.c
>>> +++ b/drivers/phy/ti/phy-j721e-wiz.c
>>> @@ -450,8 +450,8 @@ static int wiz_mode_select(struct wiz *wiz)
>>>  		} else if (wiz->lane_phy_type[i] == PHY_TYPE_USXGMII) {
>>>  			ret = regmap_field_write(wiz->p0_mac_src_sel[i], 0x3);
>>>  			ret = regmap_field_write(wiz->p0_rxfclk_sel[i], 0x3);
>>
>> I'm not sure. Don't we have to change rxfclk as well?
> 
> This patch was validated on a custom board with the J7200 SR 2.0 SoC.
> The signal corresponding to the USXGMII lane of the SERDES was measured
> to be 5 Gbps without this patch and 10 Gbps with this patch applied,
> with no other changes required. Apart from measuring the signal, ping
> was also validated.

Thanks. This is useful piece off information that could go in the commit log.

Reviewed-by: Roger Quadros <rogerq@kernel.org>

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