Re: [PATCH net-next 04/13] ravb: Add ptp_cfg_active to struct ravb_hw_info

From: Sergei Shtylyov <sergei.shtylyov@gmail.com>
To: Biju Das <biju.das.jz@bp.renesas.com>,
	Sergey Shtylyov <s.shtylyov@omp.ru>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Adam Ford <aford173@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>
Subject: Re: [PATCH net-next 04/13] ravb: Add ptp_cfg_active to struct ravb_hw_info
Date: Thu, 26 Aug 2021 21:06:44 +0300	[thread overview]
Message-ID: <93dab08c-4b0b-091d-bd47-6e55bce96f8a@gmail.com> (raw)
In-Reply-To: <OS0PR01MB5922F8114A505A33F7A47EB586C79@OS0PR01MB5922.jpnprd01.prod.outlook.com>

On 8/26/21 1:52 PM, Biju Das wrote:
[...]
>>>>>>> There are some H/W differences for the gPTP feature between R-Car
>>>>>>> Gen3, R-Car Gen2, and RZ/G2L as below.
>>>>>>>
>>>>>>> 1) On R-Car Gen3, gPTP support is active in config mode.
>>>>>>> 2) On R-Car Gen2, gPTP support is not active in config mode.
>>>>>>> 3) RZ/G2L does not support the gPTP feature.
>>>>>>>
>>>>>>> Add a ptp_cfg_active hw feature bit to struct ravb_hw_info for
>>>>>>> supporting gPTP active in config mode for R-Car Gen3.
>>>>>>
>>>>>>      Wait, we've just done this ion the previous patch!
>>>>>>
>>>>>>> This patch also removes enum ravb_chip_id, chip_id from both
>>>>>>> struct ravb_hw_info and struct ravb_private, as it is unused.
>>>>>>>
>>>>>>> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
>>>>>>> Reviewed-by: Lad Prabhakar
>>>>>>> <prabhakar.mahadev-lad.rj@bp.renesas.com>
>>>>>>> ---
>>>>>>>    drivers/net/ethernet/renesas/ravb.h      |  8 +-------
>>>>>>>    drivers/net/ethernet/renesas/ravb_main.c | 12 +++++-------
>>>>>>>    2 files changed, 6 insertions(+), 14 deletions(-)
>>>>>>>
>>>>>>> diff --git a/drivers/net/ethernet/renesas/ravb.h
>>>>>>> b/drivers/net/ethernet/renesas/ravb.h
>>>>>>> index 9ecf1a8c3ca8..209e030935aa 100644
>>>>>>> --- a/drivers/net/ethernet/renesas/ravb.h
>>>>>>> +++ b/drivers/net/ethernet/renesas/ravb.h
>>>>>>> @@ -979,17 +979,11 @@ struct ravb_ptp {
>>>>>>>    	struct ravb_ptp_perout perout[N_PER_OUT];  };
>>>>>>>
>>>>>>> -enum ravb_chip_id {
>>>>>>> -	RCAR_GEN2,
>>>>>>> -	RCAR_GEN3,
>>>>>>> -};
>>>>>>> -
>>>>>>>    struct ravb_hw_info {
>>>>>>>    	const char (*gstrings_stats)[ETH_GSTRING_LEN];
>>>>>>>    	size_t gstrings_size;
>>>>>>>    	netdev_features_t net_hw_features;
>>>>>>>    	netdev_features_t net_features;
>>>>>>> -	enum ravb_chip_id chip_id;
>>>>>>>    	int stats_len;
>>>>>>>    	size_t max_rx_len;
>>>>>>
>>>>>>      I would put the above in a spearte patch...
>>>>
>>>>      Separate. :-)
>>>>
>>>>>>>    	unsigned aligned_tx: 1;
>>>>>>> @@ -999,6 +993,7 @@ struct ravb_hw_info {
>>>>>>>    	unsigned tx_counters:1;		/* E-MAC has TX counters */
>>>>>>>    	unsigned multi_irqs:1;		/* AVB-DMAC and E-MAC has
>>>> multiple
>>>>>> irqs */
>>>>>>>    	unsigned no_ptp_cfg_active:1;	/* AVB-DMAC does not support
>>>> gPTP
>>>>>> active in config mode */
>>>>>>> +	unsigned ptp_cfg_active:1;	/* AVB-DMAC has gPTP support
>> active in
>>>>>> config mode */
>>>>>>
>>>>>>      Huh?
>>>>>>
>>>>>>>    };
>>>>>>>
>>>>>>>    struct ravb_private {
>>>>>> [...]
>>>>>>> @@ -2216,7 +2213,7 @@ static int ravb_probe(struct platform_device
>>>>>> *pdev)
>>>>>>>    	INIT_LIST_HEAD(&priv->ts_skb_list);
>>>>>>>
>>>>>>>    	/* Initialise PTP Clock driver */
>>>>>>> -	if (info->chip_id != RCAR_GEN2)
>>>>>>> +	if (info->ptp_cfg_active)
>>>>>>>    		ravb_ptp_init(ndev, pdev);
>>>>>>
>>>>>>      What's that? Didn't you touch this lie in patch #3?
>>>>>>
>>>>>>      This seems lie a NAK bait... :-(
>>>>>
>>>>> Please refer the original patch[1] which introduced gPTP support
>>>>> active
>>>> in config mode.
>>>>> I am sure this will clear all your doubts.
>>>>
>>>>      It hasn't. Why do we need 2 bit fields (1 "positive" and 1
>>>> "negative") for the same feature is beyond me.
>>>
>>> The reason is mentioned in commit description, Do you agree 1, 2 and 3
>> mutually exclusive?
>>>
>>> 1) On R-Car Gen3, gPTP support is active in config mode.
>>> 2) On R-Car Gen2, gPTP support is not active in config mode.
>>> 3) RZ/G2L does not support the gPTP feature.
>>
>>     No, (1) includes (2).
> 
> patch[1] is for supporting gPTP support active in config mode.

   Yes.

> Do you agree GAC register(gPTP active in Config) bit in AVB-DMAC mode register(CCC) present only in R-Car Gen3?

   Yes.
   But you feature naming is totally misguiding, nevertheless...

> [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/net/ethernet/renesas/ravb_main.c?h=next-20210825&id=f5d7837f96e53a8c9b6c49e1bc95cf0ae88b99e8
> 
> Regards,
> Biju

[...]

MBR, Sergey