Re: Synopsys Ethernet QoS Driver

From: Joao Pinto
Date: Mon Nov 21 2016 - 10:00:29 EST

On 21-11-2016 14:36, Giuseppe CAVALLARO wrote:
> Hello Joao
> On 11/21/2016 2:48 PM, Joao Pinto wrote:
>> Synopsys QoS IP is a separated hardware component, so it should be reusable by
>> all implementations using it and so have its own "core driver" and platform +
>> pci glue drivers. This is necessary for example in hardware validation, where
>> you prototype an IP and instantiate its drivers and test it.
>> Was there a strong reason to integrate QoS features directly in stmmac and not
>> in synopsys/dwc_eth_qos.*?
> We decided to enhance the stmmac on supporting the QoS for several
> reasons; for example the common APIs that the driver already exposed and
> actually suitable for other SYNP chips. Then, PTP, EEE,
> S/RGMII, MMC could be shared among different chips with a minimal
> effort. This meant a lot of code already ready.
> For sure, the net-core, Ethtool, mdio parts were reused. Same for the
> glue logic files.
> For the latter, this helped to easily bring-up new platforms also
> because the stmmac uses the HW cap register to auto-configure many
> parts of the MAC core, DMA and modules. This helped many users, AFAIK.
> For validation purpose, this is my experience, the stmmac helped
> a lot because people used the same code to validate different HW
> and it was easy to switch to a platform to another one in order to
> verify / check if the support was ok or if a regression was introduced.
> This is important for complex supports like PTP or EEE.
> Hoping this can help.
> Do not hesitate to contact me for further details

Thanks for the highly detailed info.
My target application is to prototype the Ethernet QoS IP in a FPGA, with a PHY
attached and make hardware validation.

In your opinion a refactored stmmac with the missing QoS features would be
suitable for it?


> peppe