ethtool: Pause frame reporting fixes

Hello. Our software needs to modify pause parameters dynamically.
For this to work reliably the SUPPORTED_Pause and SUPPORTED_Asym_Pause
flags need to be set correctly by the driver. As it turns out, some drivers
leave them at zero even though they implement pause frames.
This patch adds reporting for these flags to ethtool.
For some reason the current code reports ADVERTISED_Pause
but not SUPPORTED_Pause. Also there was a small bug
in the reporting for ADVERTISED_Pause.

Esa-Pekka Pyokkimies, Software Specialist, Stonesoft

 ethtool.c |   19 ++++++++++++++++---
 1 files changed, 16 insertions(+), 3 deletions(-)

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On Tue, 2011-05-24 at 10:58 +0000, Esa-Pekka Pyökkimies wrote:
> Hello. Our software needs to modify pause parameters dynamically.
> For this to work reliably the SUPPORTED_Pause and SUPPORTED_Asym_Pause
> flags need to be set correctly by the driver. As it turns out, some drivers
> leave them at zero even though they implement pause frames.
> This patch adds reporting for these flags to ethtool.
> For some reason the current code reports ADVERTISED_Pause
> but not SUPPORTED_Pause.

Yes, that seems to be a bug.

Note that some drivers do change pause advertising flags in response to
the ETHTOOL_SPAUSEPARAM command (ethtool -A) if the command enables
autoneg.

> Also there was a small bug
> in the reporting for ADVERTISED_Pause.

No, it matches table 28B-2 in IEEE 802.3 (though with different
terminology).

> Esa-Pekka Pyokkimies, Software Specialist, Stonesoft

Any patches for ethtool need to include a Developer's Certificate of
Origin, as for the kernel - see
<http://www.kernel.org/doc/Documentation/SubmittingPatches>.

Please resubmit with the 'supported' flags decoded in conformance with
IEEE 802.3.

Ben.

>  ethtool.c |   19 ++++++++++++++++---
>  1 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/ethtool.c b/ethtool.c
> index 34fe107..cf6c4b2 100644
> --- a/ethtool.c
> +++ b/ethtool.c
> @@ -1193,6 +1193,19 @@ static void dump_supported(struct ethtool_cmd *ep)
>  		did1++; fprintf(stdout, "10000baseT/Full ");
>  	}
>  	fprintf(stdout, "\n");
> +        
> +	fprintf(stdout, "	Supported pause frame use: ");
> +	if (mask & SUPPORTED_Pause) {
> +		if (mask & SUPPORTED_Asym_Pause)
> +			fprintf(stdout, "Receive-only\n");
> +		else
> +			fprintf(stdout, "Symmetric\n");
> +	} else {
> +		if (mask & SUPPORTED_Asym_Pause)
> +			fprintf(stdout, "Transmit-only\n");
> +		else
> +			fprintf(stdout, "No\n");
> +        }
>  
>  	fprintf(stdout, "	Supports auto-negotiation: ");
>  	if (mask & SUPPORTED_Autoneg)
> @@ -1255,10 +1268,10 @@ static void dump_advertised(struct ethtool_cmd *ep,
>  
>  	fprintf(stdout, "	%s pause frame use: ", prefix);
>  	if (mask & ADVERTISED_Pause) {
> -		fprintf(stdout, "Symmetric");
>  		if (mask & ADVERTISED_Asym_Pause)
> -			fprintf(stdout, " Receive-only");
> -		fprintf(stdout, "\n");
> +			fprintf(stdout, "Receive-only\n");
> +                else
> +			fprintf(stdout, "Symmetric\n");
>  	} else {
>  		if (mask & ADVERTISED_Asym_Pause)
>  			fprintf(stdout, "Transmit-only\n");