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 79B6B23DE; Tue, 29 Jul 2025 17:34:09 +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=1753810449; cv=none; b=JIETLE5QhfwsyABMsREfJec/l8hFALBbEM4TCbU/1CH66JszEklWT56fxSrdevT3ArftEYdjUQURzlBFCVuXVm4fJCOCLKgFL4M0w1q9Fx81eSHicw0sojQ27hVANZDgHr20eR75i8C/0qVA2zG99WXnK2q8uSr23aS3Oo6wLmA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753810449; c=relaxed/simple; bh=gqjJxvrbJzU+Y1NaVhsDYvQYmRoqY8d4rd0tdxvq+Yk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eakSyGE9z6MkG0gQ6NLc1peEB9jxmkIXZ0WSSxeupP/3QvmFcw0JfIisCzSOGBuQY0/Wk0U0BmrJ/lSsq/NJio0f93kABNiEU0mNxtn+32x97Z8Z6s4o1mtGLgDCRUVUg7hV+XGWo3u2wahHXY0pb7gzworRt4Fe2ka6z6d5KfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eabzNBFb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eabzNBFb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCAE0C4CEEF; Tue, 29 Jul 2025 17:34:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753810449; bh=gqjJxvrbJzU+Y1NaVhsDYvQYmRoqY8d4rd0tdxvq+Yk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eabzNBFbEPWmcOna09473itgkl4JYClURyCLK83NCanQbjgmk90/+qQJY4Atgytqj rYUAH1qzzNHxQd1yjgU2/kCgl6TPIO0Wi6V37MaKbNVUOxy/qtS4t1CB9eIOH0oS4+ th0zFV34hG1n34QcTIOpj8/6/RppgfpxA9iciNRgDIeuFbjPW3LDT8Owui3zZXUiGi OuCfrzJ5zARMJfLQaie8aapd8hyBFJwp0TwOqaXm8sPlGpioGvKPZ6kOfwOJxDEW+Q agWpZZCjjMuS6hAMoOB2K03GV5vtXoQaE6RvdFwuB7KakvFjH9jFdBp8R7hMj5DJIz 0fdzZucjTtp4w== Date: Tue, 29 Jul 2025 10:34:07 -0700 From: Drew Fustini To: Yao Zi Cc: Guo Ren , Fu Wei , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , 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 0/3] Fix broken link with TH1520 GMAC when linkspeed changes Message-ID: References: <20250729093734.40132-1-ziyao@disroot.org> Precedence: bulk X-Mailing-List: devicetree@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: <20250729093734.40132-1-ziyao@disroot.org> On Tue, Jul 29, 2025 at 09:37:31AM +0000, Yao Zi wrote: > It's noted that on TH1520 SoC, the GMAC's link becomes broken after > the link speed is changed (for example, running ethtool -s eth0 speed > 100 on the peer when negotiated to 1Gbps), but the GMAC could function > normally if the speed is brought back to the initial. > > Just like many other SoCs utilizing STMMAC IP, we need to adjust the TX > clock supplying TH1520's GMAC through some SoC-specific glue registers > when linkspeed changes. But it's found that after the full kernel > startup, reading from them results in garbage and writing to them makes > no effect, which is the cause of broken link. > > Further testing shows perisys-apb4-hclk must be ungated for normal > access to Th1520 GMAC APB glue registers, which is neither described in > dt-binding nor acquired by the driver. > > This series expands the dt-binding of TH1520's GMAC to allow an extra > "APB glue registers interface clock", instructs the driver to acquire > and enable the clock, and finally supplies CLK_PERISYS_APB4_HCLK for > TH1520's GMACs in SoC devicetree. > > Yao Zi (3): > dt-bindings: net: thead,th1520-gmac: Describe APB interface clock > net: stmmac: thead: Get and enable APB clock on initialization > riscv: dts: thead: Add APB clocks for TH1520 GMACs > > .../devicetree/bindings/net/thead,th1520-gmac.yaml | 8 ++++++-- > arch/riscv/boot/dts/thead/th1520.dtsi | 10 ++++++---- > drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c | 6 ++++++ > 3 files changed, 18 insertions(+), 6 deletions(-) > > -- > 2.50.1 > Thanks for fixing this issue. I've tested this series on next-20250729 with my LPi4a. I'm able to change the speed from 1000 to 100 and back to 1000. The network continues to work without any problems through those transistions. Tested-by: Drew Fustini