From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) (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 27DA12FA62F; Wed, 18 Jun 2025 17:42:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.142.180.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750268532; cv=none; b=kbSf0JM/fTwwCgKHbOMcCzilGbQZeMBdywf84KuUAdNmpSo0LSKk7JZ2+/yb5PJIZWP/PKhGT+FlGZ7Y+ud6p6PdC6urvHBMKGDjBnjj4TSNN2D6oIqWeUw/8EBdYuO6IWPOMjOZddMM+hKoj0rktB0dpVWi6DRJAHYsOq8kY6w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750268532; c=relaxed/simple; bh=PFOvRPg2CJBPcJUPWyP7JdVspRXn33CIKGD2PUZrvUo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Iaik5aBcpnFOKmvpFZZzBEBnsRlRFa0lFigdZUboV/W3igliFxVVrHwrIOtTfP8vo2GfCPP+JtBsjGtywqsLA1e9C3KT3f9PSz5dqoCcUrJhkdbhsdbuOyByQNZpDz9ozcqZgOgWoWILyfho2uchWW5spfwS36/AvTOAJOZV6C4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org; spf=pass smtp.mailfrom=makrotopia.org; arc=none smtp.client-ip=185.142.180.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=makrotopia.org Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.98.2) (envelope-from ) id 1uRwez-000000004uy-0gef; Wed, 18 Jun 2025 17:41:59 +0000 Date: Wed, 18 Jun 2025 19:41:50 +0200 From: Daniel Golle To: Frank Wunderlich Cc: Felix Fietkau , Sean Wang , Lorenzo Bianconi , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Matthias Brugger , AngeloGioacchino Del Regno , Frank Wunderlich , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Simon Horman , arinc.unal@arinc9.com Subject: Re: [net-next v5 3/3] net: ethernet: mtk_eth_soc: skip first IRQ if not used Message-ID: References: <20250618130717.75839-1-linux@fw-web.de> <20250618130717.75839-4-linux@fw-web.de> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250618130717.75839-4-linux@fw-web.de> On Wed, Jun 18, 2025 at 03:07:14PM +0200, Frank Wunderlich wrote: > From: Frank Wunderlich > > On SoCs without MTK_SHARED_INT capability (all except mt7621 and > mt7628) platform_get_irq() is called for the first IRQ (eth->irq[0]) > but it is never used. I know that technically MTK_SHARED_INT is a capability flag, but it's rather a non-capability. Hardware having dedicated interrupts for RX and TX is "more capable" than (older, legacy) hardware with just one shared interrupt for both... So maybe better: "On SoCs with dedicated RX and TX interrupts (all except MT7621 and MT7628) ..." Reading the datasheet of some recent MediaTek SoC it is worth noting that there are 4 interrupts assigned to the frame engine and the FE_INT_GRP register can be used to assign functions to them. So technically, calling them RX and TX in DT is wrong, becaues they are fe_int0, fe_int1, fe_int2 and fe_int3, which are then assigned one or more functions by the driver using that FE_INT_GRP register. However, it's the driver then assigns QDMA TX to fe_int1 and RX to fe_int2 while leaving fe_int0 and fe_int3 unsued. That's what the magic value 0x21021000 which is written to FE_INT_GRP register does. On MT7988 and newer, in addition to those 4 frame engine interrupts there are **another 4** interrupts for PDMA, typically used to service 4 RX rings while one of the fe_int* is used to indicate TX done. > Skip the first IRQ and reduce the IRQ-count to 2. > > Signed-off-by: Frank Wunderlich > --- > v5: > - change commit title and description > v4: > - drop >2 condition as max is already 2 and drop the else continue > - update comment to explain which IRQs are taken in legacy way > --- > drivers/net/ethernet/mediatek/mtk_eth_soc.c | 12 ++++++++---- > drivers/net/ethernet/mediatek/mtk_eth_soc.h | 4 ++-- > 2 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > index 875e477a987b..7990c84b2b56 100644 > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c > @@ -3354,10 +3354,14 @@ static int mtk_get_irqs(struct platform_device *pdev, struct mtk_eth *eth) > * the second is for TX, and the third is for RX. > */ > for (i = 0; i < MTK_FE_IRQ_NUM; i++) { > - if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT) && i > 0) > - eth->irq[i] = eth->irq[MTK_FE_IRQ_SHARED]; > - else > - eth->irq[i] = platform_get_irq(pdev, i); > + if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT)) { > + if (i == 0) This would make it even more readable: if (i == MTK_FE_IRQ_SHARED) Other than that looks good to me: Reviewed-by: Daniel Golle > + eth->irq[MTK_FE_IRQ_SHARED] = platform_get_irq(pdev, i); > + else > + eth->irq[i] = eth->irq[MTK_FE_IRQ_SHARED]; > + } else { > + eth->irq[i] = platform_get_irq(pdev, i + 1); > + } > > if (eth->irq[i] < 0) { > dev_err(&pdev->dev, "no IRQ%d resource found\n", i); > diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h > index 8cdf1317dff5..9261c0e13b59 100644 > --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h > +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h > @@ -643,8 +643,8 @@ > #define MTK_MAC_FSM(x) (0x1010C + ((x) * 0x100)) > > #define MTK_FE_IRQ_SHARED 0 > -#define MTK_FE_IRQ_TX 1 > -#define MTK_FE_IRQ_RX 2 > +#define MTK_FE_IRQ_TX 0 > +#define MTK_FE_IRQ_RX 1 > #define MTK_FE_IRQ_NUM (MTK_FE_IRQ_RX + 1) > > struct mtk_rx_dma { > -- > 2.43.0 > >