From nobody Fri Dec 19 18:18:45 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 D8D5019E968; Thu, 4 Dec 2025 04:41:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764823292; cv=none; b=X4HNuWoEL7QL+jy7TRJD7ADTz3cyEH9YBF3CtF4k5DLKbMYFBV78m07EIPua+otA7wVYnEUteKazpKgw2C5iMpKsIfLNLUL58Cd3puufUShNCqBlHW+rd78luD7BXdSB3FzRply+KvspZ7wVzZJc2n+CG9vWnayDpgtEJt7zOdI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764823292; c=relaxed/simple; bh=wj1zTlmxZ6w8p5WL1TQZ0TATfR58M5u70uppx+bZhRs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=kjDxHemycYNSvh8Un0JYrOAuZbq5JJ+wML7BNwps5jRrAUqvQXs3UFVlmrlq32sfaKSLXNXpfC93BTHJuN8loZY6TOmNpJIk1vdfhQPD7+Pe4ry5O2Ltrs7sytC2G1dm/mnu4gtPXL8b7aY0WHpy8s6m4AXXyrcdL95fK2iQiQ4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=RNCmO7oB; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="RNCmO7oB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764823291; x=1796359291; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=wj1zTlmxZ6w8p5WL1TQZ0TATfR58M5u70uppx+bZhRs=; b=RNCmO7oBJmmH+sWasDhbtsM+gJJ8J6GjXlrXTTJf2DNyclugXuvU8YUX pkzDtWUooXMV92VDsCDBupKhY4gIutPe4S1mbuAkRO7mQnFNeHBP/JWEX mMMd5iffw/kwTBNYKIwM3gOYaLy2IT1tkY62h3wIcm7sbuIsPxb8I8r8a NkvRS10ULq87nHRgLs2JK4pazHMYQKN5b5V1HQh9kQWPyTlabo6TYA/Ar Dj8gAsOdpRtyATp9nNM2Ac9Wu2Sc0vK8k5Tgb6ncbrCj+WBefXQZbxrLI /0k6Fp6oTGBz6g+zj76MPXdnWj0KYMCcEQwJmItmtWBKV30+Zk6CVb2S+ Q==; X-CSE-ConnectionGUID: Qd6++P+IRyW+KXnBhS6V/w== X-CSE-MsgGUID: NsA5iNaIQ9ySnh3Rg+BYcQ== X-IronPort-AV: E=McAfee;i="6800,10657,11631"; a="65830529" X-IronPort-AV: E=Sophos;i="6.20,248,1758610800"; d="scan'208";a="65830529" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Dec 2025 20:41:30 -0800 X-CSE-ConnectionGUID: tY188lS6TIWhEgQ7hypAlA== X-CSE-MsgGUID: VNU1mn/lQXiGpuqnF1h2ug== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,248,1758610800"; d="scan'208";a="194703060" Received: from p2dy149cchoong.png.intel.com ([10.107.243.50]) by orviesa009.jf.intel.com with ESMTP; 03 Dec 2025 20:41:26 -0800 From: Chwee-Lin Choong To: Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Zdenek Bouska , Faizal Rahim , Aleksandr Loktionov , Paul Menzel , Simon Horman Subject: [PATCH iwl-net v2] igc: Reduce TSN TX packet buffer from 7KB to 5KB per queue Date: Thu, 4 Dec 2025 20:21:50 +0800 Message-ID: <20251204122150.23853-1-chwee.lin.choong@intel.com> X-Mailer: git-send-email 2.42.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The previous 7 KB per queue caused TX unit hangs under heavy timestamping load. Reducing to 5 KB avoids these hangs and matches the TSN recommendation in I225/I226 SW User Manual Section 7.5.4. The 8 KB =E2=80=9Cfreed=E2=80=9D by this change is currently unused. This r= eduction is not expected to impact throughput, as the i226 is PCIe-limited for small TSN packets rather than TX-buffer-limited. Fixes: 0d58cdc902da ("igc: optimize TX packet buffer utilization for TSN mo= de") Reported-by: Zdenek Bouska Closes: https://lore.kernel.org/netdev/AS1PR10MB5675DBFE7CE5F2A9336ABFA4EBE= AA@AS1PR10MB5675.EURPRD10.PROD.OUTLOOK.COM/ Reviewed-by: Paul Menzel Reviewed-by: Simon Horman Reviewed-by: Aleksandr Loktionov Signed-off-by: Chwee-Lin Choong --- v1: https://patchwork.ozlabs.org/project/intel-wired-lan/patch/202509181838= 11.31270-1-chwee.lin.choong@intel.com/ changelog: v1 -> v2=20 - Elaborated commit message --- drivers/net/ethernet/intel/igc/igc_defines.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/eth= ernet/intel/igc/igc_defines.h index 498ba1522ca4..9482ab11f050 100644 --- a/drivers/net/ethernet/intel/igc/igc_defines.h +++ b/drivers/net/ethernet/intel/igc/igc_defines.h @@ -443,9 +443,10 @@ #define IGC_TXPBSIZE_DEFAULT ( \ IGC_TXPB0SIZE(20) | IGC_TXPB1SIZE(0) | IGC_TXPB2SIZE(0) | \ IGC_TXPB3SIZE(0) | IGC_OS2BMCPBSIZE(4)) +/* TSN value following I225/I226 SW User Manual Section 7.5.4 */ #define IGC_TXPBSIZE_TSN ( \ - IGC_TXPB0SIZE(7) | IGC_TXPB1SIZE(7) | IGC_TXPB2SIZE(7) | \ - IGC_TXPB3SIZE(7) | IGC_OS2BMCPBSIZE(4)) + IGC_TXPB0SIZE(5) | IGC_TXPB1SIZE(5) | IGC_TXPB2SIZE(5) | \ + IGC_TXPB3SIZE(5) | IGC_OS2BMCPBSIZE(4)) =20 #define IGC_DTXMXPKTSZ_TSN 0x19 /* 1600 bytes of max TX DMA packet size */ #define IGC_DTXMXPKTSZ_DEFAULT 0x98 /* 9728-byte Jumbo frames */ --=20 2.43.0