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 0B6944A1DE4 for ; Thu, 15 Oct 2026 07:44:11 +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=1792050254; cv=none; b=gHH9bFZjyF8WoMHFfyx7DC7HmfxNF3MpfcYlvuZgez9yl5tc3pg1OAyNNbNYbMXO6aG04esdEjwKMz0pCvifZ0YJ318840pheXphudBwsEdVVgnL8eA4oBkS6m7mJsxuIpiL4plGpTZ6Cl26SG7deCEVWq787opuI5gJi9UF3hY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792050254; c=relaxed/simple; bh=ryGiRNqiCIQNS47E0+1j+d0OvgHVyPz+MuQBWUaCXRo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uG3IQ/vM3j9BUwYbKbV8mwb6lMknbqPraKXHM3Q8h1R7oi45ppUiNo1FUOcyFbgPNKuVmB5kkFiVvcBAF7nBHm5uEeyRMB61oxIhqAooVm6QhF8El++lOCJmylEEejxB9DglEscERsAXfZJsKS1HbfAlJobZkcV7d6rFvmKFflg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J0a+FVn4; 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="J0a+FVn4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08B3E1F000C4; Thu, 15 Oct 2026 07:44:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792050251; bh=LEG361a6pDP+9DS65uWsMHb0ylN+/ee1WZlLzfsbLsw=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=J0a+FVn4WjRhHJ38DOu0W5/c8zAoX3QZ/kESKgLIx9ZhrIZoPfjBEpPHpJGpAFKkE xuMX87ZqJjES76RQ/NYKYDv348s/FfCaN7UEtUnAnldt4dK67MnxjUIc+jjisg17DD jWts+Ry4O0MdlYxGpXINFk+B896R8xt/zGhrwUeZhvAS10DRFqVRHuspHfQIqgk7IE tyrKQktT1GgGykGoYP+6vDITeeawDmRqaLQOgr8KkQmaOdqpDzrCO7ll9S04y3Kvg7 05TCBMLJl1+L5GaDV2zAL1Erjjr+h0E4YzOkInoESwbJbnHxqfqBFyQEJKd+DYu5w9 bXba4Ztf36dig== Date: Thu, 15 Oct 2026 09:44:09 +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 v3] net: airoha: keep PPE offload when NPU refuses flow stats Message-ID: References: <20261008094828.15458-1-sayantann11@gmail.com> <20261015045607.12999-1-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="as81oyFgOPbUaC9b" Content-Disposition: inline In-Reply-To: <20261015045607.12999-1-sayantann11@gmail.com> --as81oyFgOPbUaC9b 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. 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 entries are available, clear PSE_PORT6_SHARE_DIS so > that PSE port 6 (CDM3 path to the NPU) participates in shared-buffer > flow control. PSE_FC_CFG bits 26:16 control per-port whether flow > control considers the shared buffer pool. Bit 22 is port 6. >=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 Acked-by: Lorenzo Bianconi > --- >=20 > Changes since v2: > - Drop flow_stats_cap entirely (Lorenzo). > - Keep the original airoha_ppe_get_num_stats_entries() checks (Lorenzo). > - Guard airoha_fe_clear() with sram_num_stats_entries > 0 (Lorenzo). > - Replace the error assignment and goto with a direct if check and > dev_warn() (Lorenzo). >=20 > Changes since v1: > - Explain the NPU SRAM allocation separately from the host-side DMA > buffer (Lorenzo). > - Use airoha_fe_clear() and shorten the warning message (Lorenzo). > - Include hardware testing information requested by netdev-bot. >=20 > drivers/net/ethernet/airoha/airoha_npu.c | 8 ++++++++ > drivers/net/ethernet/airoha/airoha_ppe.c | 10 ++++++---- > drivers/net/ethernet/airoha/airoha_regs.h | 2 ++ > 3 files changed, 16 insertions(+), 4 deletions(-) >=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..74ac3791cb63 100644 > --- a/drivers/net/ethernet/airoha/airoha_ppe.c > +++ b/drivers/net/ethernet/airoha/airoha_ppe.c > @@ -144,6 +144,9 @@ 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 (sram_num_stats_entries > 0) > + airoha_fe_clear(eth, PSE_FC_CFG, PSE_PORT6_SHARE_DIS); > + > 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); > @@ -1454,10 +1457,9 @@ static int airoha_ppe_offload_setup(struct airoha_= eth *eth) > =20 > ppe_num_stats_entries =3D airoha_ppe_get_total_num_stats_entries(ppe); > 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 (npu->ops.ppe_init_stats(npu, ppe->foe_stats_dma, > + ppe_num_stats_entries)) > + dev_warn(eth->dev, "NPU refused flow stats\n"); > } > =20 > airoha_ppe_hw_init(ppe); > 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 --as81oyFgOPbUaC9b Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCatCESAAKCRA6cBh0uS2t rM+IAP9ikDHBBKnIbhaPOyfL3BDcnLXD91dFbc2vkrCv0RzncQEAo+k88MojIK0p bkxd6hs4y7q3pCPiAxtvnW5InsrHnQI= =UXx2 -----END PGP SIGNATURE----- --as81oyFgOPbUaC9b--