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 C5724CEB2C7 for ; Sat, 15 Nov 2025 09:31:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Subject:Message-ID:MIME-Version:To:Cc:Date:References:Content-Type: In-Reply-To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=El1dag7V1MQtuD7usBgnxi59sc6/YKeG1sIluoJStD4=; b=b04B/grRkG3ZK2raV6vcmzKAeb 3HHa7HkxQAyCWr021i+3Mu2wFH37kkKcqth9TgqtcN/I0FunQJWEz0WDpw/fj1283CMz820sSm6mu wY0j2eiNd3TIRtR22gcL74U2HN3yLmPmefQ4lGKjq6g27DvdGegLjnuu98niwXkL55/CQYvsERueC 8uxw4HRYhm920Bgm46JfZR5IHsL27+aeM1is0fyiCstIPoSwOU1eB/jjRuP/ySBk48VEKKTnpk2Cj 8B+94TQ8gJzUy/IcM+8OdqDf5Qyx8T12KqpRLLH+KVTnJb+KHddjLlBfqaRhUEnIFtj+38qk8ZR/6 irXPCF0g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vKCcT-0000000DeK6-0Lpr; Sat, 15 Nov 2025 09:30:57 +0000 Received: from mail1.manjaro.org ([2a01:4f8:c010:b6e8::1]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vKCcQ-0000000DeJU-0edI; Sat, 15 Nov 2025 09:30:55 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id 03B7B410BC; Sat, 15 Nov 2025 10:30:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=dkim; t=1763199051; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=El1dag7V1MQtuD7usBgnxi59sc6/YKeG1sIluoJStD4=; b=rALV1oViAYxtYolAplpe2osiF+FOHCNX5Zx4T78qVIAzpsI1P2sQMI+cBw5f0RDEU4PviC +moZ/vT0+43hjexj07jGbJ4ZgBKjQ9DRS4mru2wuvcL8whV6J2iihBOtFDqyRl6h/+C4HE x/oJMiYsjdJCJg8nasrf8r4Bl6kPFVCklPbxEGgXTMtFG34k+F5fw4JOFIgsHw6RqhIyPN zjNqskWy/iR02hg2Rh1akcoc5o76JFhf2BSNjnILcjPqMM8HUY4/DehS0h5Gp7MeLr4xLz AEW/Qtq6d2WskL0FDa5GyZqFRHaYa/VgUDM3KJSwGRwqIMqhrSatPVvYdfnQfg== From: "Dragan Simic" In-Reply-To: Content-Type: text/plain; charset="utf-8" References: Date: Sat, 15 Nov 2025 10:30:49 +0100 Cc: linux-rockchip@lists.infradead.org, "Shawn Lin" , "Lorenzo Pieralisi" , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , "Manivannan Sadhasivam" , "Rob Herring" , "Bjorn Helgaas" , "Heiko Stuebner" , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, "Krzysztof Kozlowski" , "Conor Dooley" , "Johan Jonker" To: "Geraldo Nascimento" MIME-Version: 1.0 Message-ID: Subject: =?utf-8?q?Re=3A?= [PATCH 2/3] =?utf-8?q?PCI=3A?= =?utf-8?q?_rockchip-host=3A?= comment danger of =?utf-8?q?5=2E0?= GT/s speed User-Agent: SOGoMail 5.12.3 Content-Transfer-Encoding: quoted-printable X-Last-TLS-Session-Version: None X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251115_013054_348068_FE462079 X-CRM114-Status: GOOD ( 12.86 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello Geraldo, On Saturday, November 15, 2025 10:10 CET, Geraldo Nascimento wrote: > According to Rockchip sources, there is grave danger in enabling 5.0 > GT/s speed for this core. Add a comment documenting that danger and > discouraging end-users from forcing higher speed through DT changes. >=20 > Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21= b@rock-chips.com/ > Reported-by: Shawn Lin > Signed-off-by: Geraldo Nascimento > --- > drivers/pci/controller/pcie-rockchip-host.c | 5 +++++ > 1 file changed, 5 insertions(+) >=20 > diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pc= i/controller/pcie-rockchip-host.c > index ee1822ca01db..7e6ff76466b7 100644 > --- a/drivers/pci/controller/pcie-rockchip-host.c > +++ b/drivers/pci/controller/pcie-rockchip-host.c > @@ -332,6 +332,11 @@ static int rockchip=5Fpcie=5Fhost=5Finit=5Fport(= struct rockchip=5Fpcie *rockchip) > /* > * Enable retrain for gen2. This should be configured only after > * gen1 finished. > + * > + * According to Rockchip this path is dangerous and may lead to > + * catastrophic failure. Even if the odds are small, users are > + * still discouraged to engage the corresponding DT option. > + * > */ > status =3D rockchip=5Fpcie=5Fread(rockchip, PCIE=5FRC=5FCONFIG=5FC= R + PCI=5FEXP=5FLNKCTL2); > status &=3D ~PCI=5FEXP=5FLNKCTL2=5FTLS; Looking good to me, thanks for this patch! There's no need to emit warnings here, because they'd be emitted already in the rockchip=5Fpcie=5Fparse=5Fdt() function. Please feel free to include Reviewed-by: Dragan Simic