From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6F75A2FF178; Wed, 28 Jan 2026 15:51:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615496; cv=none; b=WJQdWAl62d3feH1SUcRmu6NMMxeEv+kn6arkxSYBOglSs+ODDZ1PRQWbvqDYCFwpiWbtCdjLFbJoowOhX6OdneWzZc/m75lgqYuYSTb1eXyf91tUYxToWc+Ni7u/x4TftXFpTp7rhiY7SMJR1fYA6tNnzYrnCNa4qj4M/IyjxGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769615496; c=relaxed/simple; bh=26Ww30JpgaZ33Bfi11SfwtKiA8yP8hImrEy5ytVjtNE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=unzQ9yBR8pNwP9jNnmVDYcNFGaML/EJPwOLUgrAIC1Wu31rFw9iPjF08eZy6AAIFcY7joMVoXIQ/ILzEx3ApSywDoJwdKnPvLoun7mES7n2nvgVH94vmqIAdQMPmRG7E4U3pUL2TY0MO1g/tOGm5I57/x3MeW4anTITEuYR7X8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=g5e66FHs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="g5e66FHs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEAECC4CEF1; Wed, 28 Jan 2026 15:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769615496; bh=26Ww30JpgaZ33Bfi11SfwtKiA8yP8hImrEy5ytVjtNE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g5e66FHsKgW+eutmYlOFn7nYmIWqMFHdBB1uTHQZQkNNvPcuk2OEJkyPgNQXTnsRR FqgsT3j+OuHMhp25aSmv5mHbfWBtoLlIAh3W9FVZsQKkkLTXvHrDxrKZ7tQq9bRTDh eI6vIXl2ZZn6mO+IH4qxIaxUM8pkirhQAj78sDyw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zdenek Bouska , Paul Menzel , Simon Horman , Aleksandr Loktionov , Chwee-Lin Choong , Avigail Dahan , Tony Nguyen , Sasha Levin Subject: [PATCH 6.18 026/227] igc: Reduce TSN TX packet buffer from 7KB to 5KB per queue Date: Wed, 28 Jan 2026 16:21:11 +0100 Message-ID: <20260128145345.287593477@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260128145344.331957407@linuxfoundation.org> References: <20260128145344.331957407@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chwee-Lin Choong [ Upstream commit 8ad1b6c1e63d25f5465b7a8aa403bdcee84b86f9 ] 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 "freed" by this change is currently unused. This reduction 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 mode") Reported-by: Zdenek Bouska Closes: https://lore.kernel.org/netdev/AS1PR10MB5675DBFE7CE5F2A9336ABFA4EBEAA@AS1PR10MB5675.EURPRD10.PROD.OUTLOOK.COM/ Reviewed-by: Paul Menzel Reviewed-by: Simon Horman Reviewed-by: Aleksandr Loktionov Signed-off-by: Chwee-Lin Choong Tested-by: Avigail Dahan Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- 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/ethernet/intel/igc/igc_defines.h index 498ba1522ca4d..9482ab11f050f 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)) #define IGC_DTXMXPKTSZ_TSN 0x19 /* 1600 bytes of max TX DMA packet size */ #define IGC_DTXMXPKTSZ_DEFAULT 0x98 /* 9728-byte Jumbo frames */ -- 2.51.0