From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 15695472F8C for ; Fri, 9 Oct 2026 07:44:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791531887; cv=none; b=cCe6rfEat6UE/CdETxNVV2NxGdn8UA7Sb8MLj4J/H3RflY4o5cOz3e/vyqyhw4xxZqCR4maPRPxQoWGSShHa0aMxD3sDIntss4xr2npnjR7nLVQmyrIawBeKtWYMV6AvKwBQ8S7nOTqPQS3JH0AooLHV7UcALex+HVpn8WrlDnA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791531887; c=relaxed/simple; bh=2kHPMd3GoQb0XEVh+otV2yFvvOBNUJ1tqvMy8Z4qFgY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aV4Uu/CZv84qZGzChj8MufwBdmMD2+QhYsrnT2QTUg2A0hhQWPtJsj/QRGS3Ea4GWdLalsZ+vYug74xCBQlwRGW5Q1EwrbyBED7QVBdwf034Dt4M+StVYOPXgpkjAxadWUuz+Sk6XwojQyvwePCvFDNLDWh8FcCMckn+NvbKzYg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IcW0L1sz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IcW0L1sz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2711F1F00893; Fri, 9 Oct 2026 07:44:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791531885; bh=NpZ7XaceTucaY86C62zOlPu+VQmlzvfFU9YRREd4CxU=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=IcW0L1szOmI+K95UFpUOxmCcHjnJ/pBfcccJqrW7jxT91VyW1LYAoh/NpoDt22f+g n+jWOzIjD+F8l65MyLNfs0AxpindYSVONDRDZNjD/e9aI7Mi+l+MmfyJKPgSEcegjK 2tO/g1zVojMkYR7tAsQHApQS9YfwqNImgRyNOa3rgtqS4IJJuD+fV2jzCITHXCzij0 D+rN4JoP/hNwjzoH4+yfqy9MA/mHhYddOSeJRCw/SYa4I2Q3fxsQPyhBOV4l105JMC MrkHUTOE72EeYz1S2zQLcihgZQfJxzlkuv4hLq98W2DFuEBnnCmWa/3CK+/ab/MBw7 g8VREvLkZ57PA== Date: Fri, 9 Oct 2026 09:44:43 +0200 From: Lorenzo Bianconi To: SAYANTAN NANDY Cc: netdev@vger.kernel.org, andrew+netdev@lunn.ch, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, bread.hsu@airoha.com, sayantan.nandy@airoha.com Subject: Re: [PATCH net v2] net: airoha: keep PPE offload when NPU refuses flow stats Message-ID: References: <20261008094828.15458-1-sayantann11@gmail.com> <20261009050322.39060-1-sayantann11@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="NOajDJ9cSUpeZ4E4" Content-Disposition: inline In-Reply-To: <20261009050322.39060-1-sayantann11@gmail.com> --NOajDJ9cSUpeZ4E4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > From: Chad Monroe >=20 > With flow stats enabled, PPE offload setup requests flow statistics > from the NPU. If the running NPU firmware does not support flow > counters, the request fails and the current setup path aborts PPE > offload. >=20 > Treat flow statistics as an optional capability so that a failure to > set up the counters does not prevent normal PPE offload. Record > whether flow statistics are available and continue PPE initialization > when the NPU refuses the flow-statistics request. >=20 > Also treat a zero NPU statistics address returned by the firmware as a > refusal. The host-side DMA buffer (foe_stats_dma) is allocated by > dmam_alloc_coherent() in airoha_ppe_init() from system memory. The NPU > statistics address (npu_stats_addr) is a separate allocation from the > NPU firmware's internal SRAM pool. When that pool is exhausted, the > firmware replies with success and npu_stats_addr =3D 0. A zero address > does not provide a usable counter region and must not be passed to > devm_ioremap(). >=20 > When flow stats are available, clear PSE_PORT6_SHARE_DIS so that PSE > port 6 (CDM3 path to the NPU) participates in shared-buffer flow > control, which the counter traffic path needs. >=20 > When flow statistics are unavailable, PPE continues to operate without > NPU flow counters while retaining normal offload functionality. >=20 > This combines the original SmartRG/Airoha fixes for: > - keeping PPE offload active when the NPU refuses flow statistics > - treating a zero NPU statistics address as a flow-statistics refusal >=20 > Based on the original SmartRG/Airoha work by Chad Monroe: > 5ce96ab ("SDG-9458: keep PPE offload when NPU refuses flow stats") > 0ad8528 ("SDG-9458: airoha: treat a zero NPU stats address as a refusal") > Fixes: b81e0f2b58be ("net: airoha: Add FLOW_CLS_STATS callback support") > Tested-on: AN7581 with MT7992 > Signed-off-by: Chad Monroe > Signed-off-by: SAYANTAN NANDY > --- >=20 > Changes since v1: > - Rename flow_stats to flow_stats_cap (Lorenzo). > - Explain that npu_stats_addr is an NPU firmware SRAM allocation, > distinct from the host-side foe_stats_dma buffer (Lorenzo). > - Explain why PSE_PORT6_SHARE_DIS is cleared for counter traffic > (Lorenzo). > - Use airoha_fe_clear() and shorten the warning message (Lorenzo). > - Add hardware testing information requested by netdev-bot. >=20 > drivers/net/ethernet/airoha/airoha_eth.h | 1 + > drivers/net/ethernet/airoha/airoha_npu.c | 8 ++++++++ > drivers/net/ethernet/airoha/airoha_ppe.c | 17 +++++++++++------ > drivers/net/ethernet/airoha/airoha_regs.h | 2 ++ > 4 files changed, 22 insertions(+), 6 deletions(-) >=20 > diff --git a/drivers/net/ethernet/airoha/airoha_eth.h b/drivers/net/ether= net/airoha/airoha_eth.h > index 8277c1c87bb3..da4a3ba69e3c 100644 > --- a/drivers/net/ethernet/airoha/airoha_eth.h > +++ b/drivers/net/ethernet/airoha/airoha_eth.h > @@ -617,6 +617,7 @@ struct airoha_ppe { > =20 > void *foe; > dma_addr_t foe_dma; > + bool flow_stats_cap; > =20 > struct rhashtable l2_flows; > =20 > diff --git a/drivers/net/ethernet/airoha/airoha_npu.c b/drivers/net/ether= net/airoha/airoha_npu.c > index 4d3195eb00f7..b32a01dbe06b 100644 > --- a/drivers/net/ethernet/airoha/airoha_npu.c > +++ b/drivers/net/ethernet/airoha/airoha_npu.c > @@ -450,6 +450,14 @@ static int airoha_npu_ppe_stats_setup(struct airoha_= npu *npu, > if (err) > goto out; > =20 > + /* The firmware reports success with a zero address when its SRAM > + * pool has no room left for the counters. > + */ > + if (!ppe_data->stats_info.npu_stats_addr) { > + err =3D -ENOSPC; > + goto out; > + } > + > npu->stats =3D devm_ioremap(npu->dev, > ppe_data->stats_info.npu_stats_addr, > size); > diff --git a/drivers/net/ethernet/airoha/airoha_ppe.c b/drivers/net/ether= net/airoha/airoha_ppe.c > index 92611802801e..0957f331478a 100644 > --- a/drivers/net/ethernet/airoha/airoha_ppe.c > +++ b/drivers/net/ethernet/airoha/airoha_ppe.c > @@ -37,10 +37,7 @@ static const struct rhashtable_params airoha_l2_flow_t= able_params =3D { > =20 > static int airoha_ppe_get_num_stats_entries(struct airoha_ppe *ppe) > { > - if (!IS_ENABLED(CONFIG_NET_AIROHA_FLOW_STATS)) > - return -EOPNOTSUPP; > - > - if (airoha_is_7583(ppe->eth)) > + if (!ppe->flow_stats_cap) > return -EOPNOTSUPP; Looking again at the code flow_stats_cap is only used here. Why do we need = it in the first place? I guess you it is enough to just not return an error in airoha_ppe_offload_setup() and log the error instead (as you did). > =20 > return PPE_STATS_NUM_ENTRIES; > @@ -144,6 +141,9 @@ static void airoha_ppe_hw_init(struct airoha_ppe *ppe) > sram_ppe_num_data_entries =3D > PPE_RAM_NUM_ENTRIES_SHIFT(sram_ppe_num_data_entries); > =20 > + if (ppe->flow_stats_cap) > + airoha_fe_clear(eth, PSE_FC_CFG, PSE_PORT6_SHARE_DIS); can you please explain what this configuration is doing? This register is n= ot documented. > + > for (i =3D 0; i < eth->soc->num_ppe; i++) { > airoha_fe_wr(eth, REG_PPE_TB_BASE(i), > ppe->foe_dma + sram_tb_size); > @@ -1456,8 +1456,11 @@ static int airoha_ppe_offload_setup(struct airoha_= eth *eth) > if (ppe_num_stats_entries > 0) { > err =3D npu->ops.ppe_init_stats(npu, ppe->foe_stats_dma, > ppe_num_stats_entries); > - if (err) > - goto error_npu_put; > + if (err) { > + dev_warn(eth->dev, "NPU refused flow stats (%d)\n", > + err); > + ppe->flow_stats_cap =3D false; please see above. > + } > } > =20 > airoha_ppe_hw_init(ppe); > @@ -1608,6 +1611,8 @@ int airoha_ppe_init(struct airoha_eth *eth) > ppe->dev.priv =3D ppe; > ppe->eth =3D eth; > eth->ppe =3D ppe; > + ppe->flow_stats_cap =3D IS_ENABLED(CONFIG_NET_AIROHA_FLOW_STATS) && > + !airoha_is_7583(eth); please see above. Regards, Lorenzo > =20 > ppe_num_entries =3D airoha_ppe_get_total_num_entries(ppe); > foe_size =3D ppe_num_entries * sizeof(struct airoha_foe_entry); > diff --git a/drivers/net/ethernet/airoha/airoha_regs.h b/drivers/net/ethe= rnet/airoha/airoha_regs.h > index 442b48c9b991..aee06c058586 100644 > --- a/drivers/net/ethernet/airoha/airoha_regs.h > +++ b/drivers/net/ethernet/airoha/airoha_regs.h > @@ -72,6 +72,8 @@ > #define PSE_CFG_OQ_RSV_MASK GENMASK(13, 0) > =20 > #define PSE_FQ_CFG 0x008c > +#define PSE_FC_CFG 0x0098 > +#define PSE_PORT6_SHARE_DIS BIT(22) > #define PSE_FQ_LIMIT_MASK GENMASK(14, 0) > =20 > #define REG_FE_PSE_BUF_SET 0x0090 > --=20 > 2.43.0 >=20 --NOajDJ9cSUpeZ4E4 Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCasibawAKCRA6cBh0uS2t rK8sAQCcVwqGDaZNFDjbktsKV7mzp98FVx4rbcZGJlo+MhlRDwD/XXQapB/RcFIs 7ItldqyvtIw7uHMNN4sLeGtM0R01uw4= =UgeO -----END PGP SIGNATURE----- --NOajDJ9cSUpeZ4E4--