From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9D17AC87FDA for ; Mon, 4 Aug 2025 05:13:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8kqmkkdtvKQGQ/j5fiJv6yKIPA6mxjkxZ5xOUCDcY7A=; b=iUcKXp7y8l+Jd0 GaTN8pIdyzYd+mFisGaqnyKSU+iaUrQ8/0yr+QcitWpnbW8c193hFYDQJSN5+31OHxxGVSK3ZU2Rm uXo/L2W2xzjH4+oems6/63thBVwP7GcijiNch7nuXXCMjk4rN+aRywUso+Y7ldBjKXRgAtnYx5Jex WoWfRkzDk0wvTMCUVUR/Q/olerfndBv2ck+RMnGmnV+Vzo1YozSXSJB3Kl0HOJLSikXG0suMjwpaM uU4IOpExtB7jkXYetx/v4TdYdOWSdVZe2AezyKQWFQEZJ4DlEq7x3Y/moEw5ds4zDMf6C5e6JQNq7 CdVFBPAsX2xs0bsVE5jg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uinVM-00000009eSg-3stI; Mon, 04 Aug 2025 05:13:00 +0000 Received: from layka.disroot.org ([178.21.23.139]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uinVK-00000009eQn-399C for linux-riscv@lists.infradead.org; Mon, 04 Aug 2025 05:13:00 +0000 Received: from mail01.disroot.lan (localhost [127.0.0.1]) by disroot.org (Postfix) with ESMTP id 5F48320A6A; Mon, 4 Aug 2025 07:12:54 +0200 (CEST) X-Virus-Scanned: SPAM Filter at disroot.org Received: from layka.disroot.org ([127.0.0.1]) by localhost (disroot.org [127.0.0.1]) (amavis, port 10024) with ESMTP id BJneWLsAwyEm; Mon, 4 Aug 2025 07:12:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=disroot.org; s=mail; t=1754284373; bh=SUW5D5b5WsWlP0YMXjvvOTVOjakybqdppS5vTfywQuo=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=KnFuzqsZn6Eu779yf9Zjp2zeH9TzXtH0ko/GWr/qkEkXclWSEbOcY7RI51Y3Q02tY v+YDuPEz3tihyNqYug7+rVri3pLwnVEmaImpCGBao2hWTPC/XTEZVfetkvLNYgbsp2 Bm47ovlo1P9xSqxzVTabKRShhrSLx+oNtJzGY56dgdJQaPHT9lPR8yk1X49EXRqvK/ b/kGzebPdI83cxvfkSHPJzCbuHPA3wJ6Y1ZdTHE51/2vmPoQK/1LhRwPDTXgs49qcP glOhiTuCkiv7ddJG7du/Wjd+a0pxoRfrGKUHvcz+N/k4Tf9SYfr2fmoRZIZgSVYmME mkS+if9wO21pA== Date: Mon, 4 Aug 2025 05:12:26 +0000 From: Yao Zi To: Rob Herring Cc: Drew Fustini , Guo Ren , Fu Wei , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Emil Renner Berthing , Jisheng Zhang , linux-riscv@lists.infradead.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net v2 2/3] net: stmmac: thead: Get and enable APB clock on initialization Message-ID: References: <20250801091240.46114-1-ziyao@disroot.org> <20250801091240.46114-3-ziyao@disroot.org> <20250803170206.GA525144-robh@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20250803170206.GA525144-robh@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250803_221259_207578_981FB5A6 X-CRM114-Status: GOOD ( 23.45 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Sun, Aug 03, 2025 at 12:02:06PM -0500, Rob Herring wrote: > On Fri, Aug 01, 2025 at 09:12:39AM +0000, Yao Zi wrote: > > It's necessary to adjust the MAC TX clock when the linkspeed changes, > > but it's noted such adjustment always fails on TH1520 SoC, and reading > > back from APB glue registers that control clock generation results in > > garbage, causing broken link. > > > > With some testing, it's found a clock must be ungated for access to APB > > glue registers. Without any consumer, the clock is automatically > > disabled during late kernel startup. Let's get and enable it if it's > > described in devicetree. > > > > Fixes: 33a1a01e3afa ("net: stmmac: Add glue layer for T-HEAD TH1520 SoC") > > Signed-off-by: Yao Zi > > Reviewed-by: Drew Fustini > > Tested-by: Drew Fustini > > --- > > drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c > > index c72ee759aae5..95096244a846 100644 > > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c > > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c > > @@ -211,6 +211,7 @@ static int thead_dwmac_probe(struct platform_device *pdev) > > struct stmmac_resources stmmac_res; > > struct plat_stmmacenet_data *plat; > > struct thead_dwmac *dwmac; > > + struct clk *apb_clk; > > void __iomem *apb; > > int ret; > > > > @@ -224,6 +225,11 @@ static int thead_dwmac_probe(struct platform_device *pdev) > > return dev_err_probe(&pdev->dev, PTR_ERR(plat), > > "dt configuration failed\n"); > > > > + apb_clk = devm_clk_get_optional_enabled(&pdev->dev, "apb"); > > The description sounds like this should not be optional. The binding > change also makes it not optional. Yes, it shouldn't be. But using the non-optional API will cause the driver fails to probe with the old (problematic) devicetree, IOW, it breaks the ABI. Comparing to unusable ethernet, failing to adjust the link speed sounds a minor point to me. Maybe we could add a comment to explain why optional API is used, or just use the non-optional one if such ABI breakages are acceptable -- for which I'd like to wait for more opinions. > Rob > Thanks, Yao Zi _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv