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x-ms-exchange-antispam-messagedata: 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 x-ms-exchange-transport-forked: True Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5696.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 9c2aed69-b19a-45d1-b219-08d87fe65a88 X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Nov 2020 10:51:00.9799 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: UewJF5RwT8HIZP2M5B2TU7wUirHtCwWUWa22LnCwBQ8g+RxP5++siVfpmu9fyKhx3cW+RfBp5BxNjQ8Pi04qig== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB4816 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Nov 02, 2020 at 12:34:11PM -0800, Florian Fainelli wrote: > On 11/1/2020 11:16 AM, Vladimir Oltean wrote: > > Now that we have a central TX reallocation procedure that accounts for > > the tagger's needed headroom in a generic way, we can remove the > > skb_cow_head call. > > > > Cc: Florian Fainelli > > Signed-off-by: Vladimir Oltean > > Reviewed-by: Florian Fainelli Florian, I just noticed that tag_brcm.c has an __skb_put_padto call, even though it is not a tail tagger. This comes from commit: commit bf08c34086d159edde5c54902dfa2caa4d9fbd8c Author: Florian Fainelli Date: Wed Jan 3 22:13:00 2018 -0800 net: dsa: Move padding into Broadcom tagger Instead of having the different master network device drivers potentially used by DSA/Broadcom tags, move the padding necessary for the switches to accept short packets where it makes most sense: within tag_brcm.c. This avoids multiplying the number of similar commits to e.g: bgmac, bcmsysport, etc. Signed-off-by: Florian Fainelli Signed-off-by: David S. Miller Do you remember why this was needed? As far as I understand, either the DSA master driver or the MAC itself should pad frames automatically. Is that not happening on Broadcom SoCs, or why do you need to pad from DSA? How should we deal with this? Having tag_brcm.c still do some potential reallocation defeats the purpose of doing it centrally, in a way. I was trying to change the prototype of struct dsa_device_ops::xmit to stop returning a struct sk_buff *, and I stumbled upon this. Should we just go ahead and pad everything unconditionally in DSA?=