Hi Peppe,
Às 8:09 AM de 7/7/2017, Giuseppe CAVALLARO escreveu:
> Hi Joao
>
> On 7/5/2017 12:34 PM, Joao Pinto wrote:
>> Hi Peppe,
>>
>> Às 8:10 AM de 6/9/2017, Giuseppe CAVALLARO escreveu:
>>> Hi Joao
>>>
>>> On 6/8/2017 8:02 PM, Joao Pinto wrote:
>>>> This patch fixes the description of the DT AVB parameters and gives
>>>> an accurate example. It was also included the base values that were
>>>> used to get the example' CBS paremeter values.
>>>>
>>>> Signed-off-by: Joao Pinto<jpi...@synopsys.com>
>>>> ---
>>>> Documentation/devicetree/bindings/net/stmmac.txt | 24
>>>> ++++++++++++++++--------
>>>> 1 file changed, 16 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt
>>>> b/Documentation/devicetree/bindings/net/stmmac.txt
>>>> index c3a7be6..707426d 100644
>>>> --- a/Documentation/devicetree/bindings/net/stmmac.txt
>>>> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
>>>> @@ -109,10 +109,10 @@ Optional properties:
>>>> [Attention] Queue 0 is reserved for legacy traffic
>>>> and so no AVB is available in this queue.
>>>> - Configure Credit Base Shaper (if AVB Mode selected):
>>>> - - snps,send_slope: enable Low Power Interface
>>>> - - snps,idle_slope: unlock on WoL
>>>> - - snps,high_credit: max write outstanding req. limit
>>>> - - snps,low_credit: max read outstanding req. limit
>>>> + - snps,send_slope: Send Slope Credit value
>>>> + - snps,idle_slope: Idle Slope Credit value
>>>> + - snps,high_credit: High Credit value
>>>> + - snps,low_credit: Low Credit value
>>>> - snps,priority: TX queue priority (Range: 0x0 to 0xF)
>>>> Examples:
>>>> @@ -143,10 +143,18 @@ Examples:
>>>> queue1 {
>>>> snps,avb-algorithm;
>>>> - snps,send_slope = <0x1000>;
>>>> - snps,idle_slope = <0x1000>;
>>>> - snps,high_credit = <0x3E800>;
>>>> - snps,low_credit = <0xFFC18000>;
>>>> + /*
>>>> + * Example AVB parameters based on:
>>>> + * Allocated Bandwidth: 40%
>>>> + * Maximum Frame size: 1000 bytes
>>>> + * Maximum Interference size: 1500 bytes
>>>> + * Port Transmit Rate: 8
>>>> + * Scaling Factor: 1024
>>>> + */
>>>> + snps,idle_slope = <0xCCC>;
>>>> + snps,send_slope = <0x1333>;
>>>> + snps,high_credit = <0x4B0000>;
>>> Thanks for having taken care about this changes, please, as required, add a
>>> cover-letter
>>> and give more information about these values that can be tuned by user and,
>>> for
>>> example,
>>> the snps,high_credit could be as default = 0xbe4000 that is a reasonable
>>> value
>>> because
>>> comes from 1522 * 8 * 1024 and LOW credit is the two complement.
>>> ^^^^^
>>> frame size ---> maximum is 16
>> I calculate the hi credit this way:
>>
>> HiCredit = BW / 100 * MaxInterferenceSize * 8 * Scaling
>>
>> Can I assume that you are considering 100% bandwidth for this example
>> channel?
>> If so, it is not correct, since the maximum bandwidth should be 75%, leaving
>> at
>> least 25% for default channel 0 (I think this is assured in the hardware).
>
> ok, I did not remember that so I let you detail with a right example this
> part
> in the doc.
>
> Well done and thanks.
No problem! I will send an example soon. Thanks.
Joao
>
> Peppe
>
>> Thanks,
>> Joao
>>
>>> Regards
>>> Peppe
>>>
>>>> + snps,low_credit = <0xFFB50000>;
>>>> snps,priority = <0x1>;
>>>> };
>>>> };
>>>
>>
>
