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 3362D34AB15; Tue, 26 Aug 2025 13:51:40 +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=1756216300; cv=none; b=tyZq495GP7F/nkKokIYHunR5PMZvwTPQsuI2/2Y9LjfgpvvBX+bgfEIQdBkD8OUjV8AA0w4qUDIpulZjVmsuVGpd8YFui3M0gg8811Kxaw3+hlJHRi0ddyYaNlMesh2nLPUNqm40V5AjmYqUBrWbhot8W7+K3FWpRpCVa7vlAlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756216300; c=relaxed/simple; bh=F7am3Jq6EM+MmzCv0F90fte9+il7faud56hIkza1NqQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LCjxxjN0sidwVqLhAIPWoQCkJqSpytis99WDDpveW4Q2CfS9mL4N9lYMkopeD+ncde2F+jDr/JkptIDtC9+0SUWdWWw6e7+E0Lfc16YKUUp7VjCpWlF/+EsnKwMafnX1mAF8KnUk/niivVhz9CbJa6L2wYJjA+qU8JGiO/cJhoo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=htN+UjTH; 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="htN+UjTH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B9875C116B1; Tue, 26 Aug 2025 13:51:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756216300; bh=F7am3Jq6EM+MmzCv0F90fte9+il7faud56hIkza1NqQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=htN+UjTHHfKdUAJbdnON0H0pz0mSxIL9P8+3zKcBiD2XNIPUHe8UsBSMu/ToI5DoK FgcPf+OaqcwRySNqV7bzzDy4cQZ7kxF8yu5DajodkkEHr5L7dfeXRkUGh3aSQDrzsc FZ+8YKpVGbqi79vgHWT8LGqNcrrtAop7fh1pxk+w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jonas Rebmann , Wei Fang , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 360/644] net: fec: allow disable coalescing Date: Tue, 26 Aug 2025 13:07:31 +0200 Message-ID: <20250826110955.329858959@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110946.507083938@linuxfoundation.org> References: <20250826110946.507083938@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jonas Rebmann [ Upstream commit b7ad21258f9e9a7f58b19595d5ceed2cde3bed68 ] In the current implementation, IP coalescing is always enabled and cannot be disabled. As setting maximum frames to 0 or 1, or setting delay to zero implies immediate delivery of single packets/IRQs, disable coalescing in hardware in these cases. This also guarantees that coalescing is never enabled with ICFT or ICTT set to zero, a configuration that could lead to unpredictable behaviour according to i.MX8MP reference manual. Signed-off-by: Jonas Rebmann Reviewed-by: Wei Fang Link: https://patch.msgid.link/20250626-fec_deactivate_coalescing-v2-1-0b217f2e80da@pengutronix.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/freescale/fec_main.c | 34 +++++++++++------------ 1 file changed, 16 insertions(+), 18 deletions(-) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 5c860eef0300..437e72110ab5 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -2727,27 +2727,25 @@ static int fec_enet_us_to_itr_clock(struct net_device *ndev, int us) static void fec_enet_itr_coal_set(struct net_device *ndev) { struct fec_enet_private *fep = netdev_priv(ndev); - int rx_itr, tx_itr; + u32 rx_itr = 0, tx_itr = 0; + int rx_ictt, tx_ictt; - /* Must be greater than zero to avoid unpredictable behavior */ - if (!fep->rx_time_itr || !fep->rx_pkts_itr || - !fep->tx_time_itr || !fep->tx_pkts_itr) - return; - - /* Select enet system clock as Interrupt Coalescing - * timer Clock Source - */ - rx_itr = FEC_ITR_CLK_SEL; - tx_itr = FEC_ITR_CLK_SEL; + rx_ictt = fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr); + tx_ictt = fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr); - /* set ICFT and ICTT */ - rx_itr |= FEC_ITR_ICFT(fep->rx_pkts_itr); - rx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->rx_time_itr)); - tx_itr |= FEC_ITR_ICFT(fep->tx_pkts_itr); - tx_itr |= FEC_ITR_ICTT(fec_enet_us_to_itr_clock(ndev, fep->tx_time_itr)); + if (rx_ictt > 0 && fep->rx_pkts_itr > 1) { + /* Enable with enet system clock as Interrupt Coalescing timer Clock Source */ + rx_itr = FEC_ITR_EN | FEC_ITR_CLK_SEL; + rx_itr |= FEC_ITR_ICFT(fep->rx_pkts_itr); + rx_itr |= FEC_ITR_ICTT(rx_ictt); + } - rx_itr |= FEC_ITR_EN; - tx_itr |= FEC_ITR_EN; + if (tx_ictt > 0 && fep->tx_pkts_itr > 1) { + /* Enable with enet system clock as Interrupt Coalescing timer Clock Source */ + tx_itr = FEC_ITR_EN | FEC_ITR_CLK_SEL; + tx_itr |= FEC_ITR_ICFT(fep->tx_pkts_itr); + tx_itr |= FEC_ITR_ICTT(tx_ictt); + } writel(tx_itr, fep->hwp + FEC_TXIC0); writel(rx_itr, fep->hwp + FEC_RXIC0); -- 2.39.5