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x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/x0CibV/49sytQrMnhEu.cIc"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250527_034514_259361_59A37A66 X-CRM114-Status: GOOD ( 26.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --Sig_/x0CibV/49sytQrMnhEu.cIc Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Paolo, > On 5/13/25 7:31 AM, Lukasz Majewski wrote: > >> On 5/4/25 4:55 PM, Lukasz Majewski wrote: =20 > >>> + /* This does 16 byte alignment, exactly what we > >>> need. > >>> + * The packet length includes FCS, but we don't > >>> want to > >>> + * include that when passing upstream as it > >>> messes up > >>> + * bridging applications. > >>> + */ > >>> + skb =3D netdev_alloc_skb(pndev, pkt_len + > >>> NET_IP_ALIGN); > >>> + if (unlikely(!skb)) { > >>> + dev_dbg(&fep->pdev->dev, > >>> + "%s: Memory squeeze, dropping > >>> packet.\n", > >>> + pndev->name); > >>> + pndev->stats.rx_dropped++; > >>> + goto err_mem; > >>> + } else { > >>> + skb_reserve(skb, NET_IP_ALIGN); > >>> + skb_put(skb, pkt_len); /* Make room > >>> */ > >>> + skb_copy_to_linear_data(skb, data, > >>> pkt_len); > >>> + skb->protocol =3D eth_type_trans(skb, > >>> pndev); > >>> + napi_gro_receive(&fep->napi, skb); > >>> + } > >>> + > >>> + bdp->cbd_bufaddr =3D > >>> dma_map_single(&fep->pdev->dev, data, > >>> + > >>> bdp->cbd_datlen, > >>> + > >>> DMA_FROM_DEVICE); > >>> + if (unlikely(dma_mapping_error(&fep->pdev->dev, > >>> + > >>> bdp->cbd_bufaddr))) { > >>> + dev_err(&fep->pdev->dev, > >>> + "Failed to map descriptor rx > >>> buffer\n"); > >>> + pndev->stats.rx_errors++; > >>> + pndev->stats.rx_dropped++; > >>> + dev_kfree_skb_any(skb); > >>> + goto err_mem; > >>> + } =20 > >> > >> This is doing the mapping and ev. dropping the skb _after_ pushing > >> the skb up the stack, you must attempt the mapping first. =20 > >=20 > > I've double check it - the code seems to be correct. > >=20 > > This code is a part of mtip_switch_rx() function, which handles > > receiving data. > >=20 > > First, on probe, the initial dma memory is mapped for MTIP received > > data. > >=20 > > When we receive data, it is processed and afterwards it is "pushed" > > up to the network stack. > >=20 > > As a last step we do map memory for next, incoming data and leave > > the function. > >=20 > > Hence, IMHO, the order is OK and this part shall be left as is. =20 >=20 > First thing first, I'm sorry for lagging behind. This fell outside my > radar. Let's keep the conversation on the new patch version, it should > help me to avoid repeating this mistake. +1 >=20 > /P >=20 Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Erika Unter HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de --Sig_/x0CibV/49sytQrMnhEu.cIc Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAmg1l7AACgkQAR8vZIA0 zr1MTQf/duDrLdfm82yHA91tF0QfoOm/ATV48YVaUyZ5+o9pkf5Smxkgalw0Yz6k cvVrgg+sxKz4YhjostoVdGGBxHB2DtLhSOMPpJwNCXT9/QpuEQBebGow6WzKSAk9 LR0ECr8KKa1jmBnYOIBnB7yocMv35GM8yjosi0qgcjXNgaQInD2MnGuPk0wZuR59 EWbbzluqK95BxyaxsyvwFXCzXv+7eZqgWVOoENrESTakLtRH5yu4JBqriFhhVS5P t4GS3tEjHLoGcZEQL1R0M+2hhjb+nWOi/oSIQ8t3+18Uafv0R/voN2sUeYV3QRnn MnkLFCQXJtqfqssr36pL7OJiEW8hzg== =rJLF -----END PGP SIGNATURE----- --Sig_/x0CibV/49sytQrMnhEu.cIc--