linuxptp-users

[Linuxptp-users] Clarification about Driver Compatibility Matrix

[Ledda W. E. <Wil...@it...>]

Hi all,
I don't understand very well why in the Compatibility matrix all Hardware timestamping drivers have the PHY column to "NA", while in the software timestamping table some have the PHY equal to "Y" and some equal to "N".

My interpretation is that, since they have the PHC support this means that they also support the timestamping in PHY. Is it the right conclusion?

Thanks

William

Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

[Richard C. <ric...@gm...>]

On Wed, Jul 31, 2013 at 09:18:48AM +0000, Ledda William EXT wrote:
> Hi all,
> I don't understand very well why in the Compatibility matrix all Hardware timestamping drivers have the PHY column to "NA", while in the software timestamping table some have the PHY equal to "Y" and some equal to "N".
> 
> My interpretation is that, since they have the PHC support this means that they also support the timestamping in PHY. Is it the right conclusion?

No, time stamping can be done in hardware in special MACs and special
PHYs. The Linux kernel does not support both at the same time, so if
you have a PTP-capable PHY attached to PTP-capable MAC, then you will
only get the MAC as a PHC.

In addition, only drivers using phylib can support PTP-capable PHYs.

HTH,
Richard

Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

[Ledda W. E. <Wil...@it...>]

Sorry Richard, but I'm stiil a bit confused about the meaning of the PHY column. Let me make an example, I have a i350 that has the igb driver. I read from the table the following table:

Driver	Hardware	                SOTS	PHC	PHY	VER
igb	Intel 82576, 82580	RAW	Y	NA	3.5

In this case, this means that I have a PTP-capable PHY attached to PTP-capable MAC?

Thanks

-----Original Message-----
From: Richard Cochran [mailto:ric...@gm...] 
Sent: 31 July 2013 16:43
To: Ledda William EXT
Cc: lin...@li...
Subject: Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

On Wed, Jul 31, 2013 at 09:18:48AM +0000, Ledda William EXT wrote:
> Hi all,
> I don't understand very well why in the Compatibility matrix all Hardware timestamping drivers have the PHY column to "NA", while in the software timestamping table some have the PHY equal to "Y" and some equal to "N".
> 
> My interpretation is that, since they have the PHC support this means that they also support the timestamping in PHY. Is it the right conclusion?

No, time stamping can be done in hardware in special MACs and special PHYs. The Linux kernel does not support both at the same time, so if you have a PTP-capable PHY attached to PTP-capable MAC, then you will only get the MAC as a PHC.

In addition, only drivers using phylib can support PTP-capable PHYs.

HTH,
Richard

Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

[Richard C. <ric...@gm...>]

On Mon, Aug 05, 2013 at 04:32:14PM +0000, Ledda William EXT wrote:

> Sorry Richard, but I'm stiil a bit confused about the meaning of the
> PHY column. Let me make an example, I have a i350 that has the igb
> driver. I read from the table the following table:
>
> Driver        Hardware                SOTS    PHC     PHY     VER
> igb           Intel 82576, 82580      RAW     Y       NA      3.5
> 
> In this case, this means that I have a PTP-capable PHY attached to PTP-capable MAC?

The PHY column reads "NA" meaning "Not Applicable." Even if you attach
a PTP capable PHY (like the National Semiconductor PHYTER) to your
i350 MAC, still you will never get any time stamps from the PHY, as
the MAC driver will intercept the SIOCSHWTSTAMP ioctl.

HTH,
Richard

Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

[Ledda W. E. <Wil...@it...>]

Thanks Richard. I can therefore conclude that if I have support for PHC means that the interface supports time stamping hardware (on MAC or PHY)? 
Sorry if I insist on this, maybe the question is stupid, but I cannot have doubts about.

Thanks a lot.

William


-----Original Message-----
From: Richard Cochran [mailto:ric...@gm...] 
Sent: 06 August 2013 09:18
To: Ledda William EXT
Cc: lin...@li...
Subject: Re: [Linuxptp-users] Clarification about Driver Compatibility Matrix

On Mon, Aug 05, 2013 at 04:32:14PM +0000, Ledda William EXT wrote:

> Sorry Richard, but I'm stiil a bit confused about the meaning of the 
> PHY column. Let me make an example, I have a i350 that has the igb 
> driver. I read from the table the following table:
>
> Driver        Hardware                SOTS    PHC     PHY     VER
> igb           Intel 82576, 82580      RAW     Y       NA      3.5
> 
> In this case, this means that I have a PTP-capable PHY attached to PTP-capable MAC?

The PHY column reads "NA" meaning "Not Applicable." Even if you attach a PTP capable PHY (like the National Semiconductor PHYTER) to your
i350 MAC, still you will never get any time stamps from the PHY, as the MAC driver will intercept the SIOCSHWTSTAMP ioctl.

HTH,
Richard