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 89E17CEB2C9 for ; Sat, 15 Nov 2025 09:25:06 +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=5W225Xb1n1INaMEh/to5gfQKJIJdb6ZwHU6TvTI7BKU=; b=ffMGcLiY5wqU9NOTkV5O7zNlMn xlJk4JKEoSB8Q6K8mT8gA7A3luee5B+T9UB8eT2b4SgrX7IN+n5+Ifz2gIsIMTrhgxXLkf7qvBzgy Iv7lai0vN5GJnOL9nbBvjWSNGQt3qGNrzhIaEaBJsacYMrvVHY33JEZn55Spm/cwxBJutWBVi2E8M UI12QUzpAK0J6zChvGt2TknfX85YMFUGFABPXjDAeBiZ3goqqgZXhXvWFkjOyvr9+MPm08xPKdegm B4uGGjRms7wSm08j1a5i75NSU6vi9T6jbZAdBOhV54JHKgPF++jxAa/Qm047ZtxnaSJC/zXysadjd FFymhIrg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vKCWg-0000000De0x-0ATi; Sat, 15 Nov 2025 09:24:58 +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 1vKCWd-0000000De04-03HB; Sat, 15 Nov 2025 09:24:56 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id 8FB35410BE; Sat, 15 Nov 2025 10:24:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=dkim; t=1763198691; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=5W225Xb1n1INaMEh/to5gfQKJIJdb6ZwHU6TvTI7BKU=; b=lYaApLAYL74+f7bKqNsVaLnxWo8PFvmZY+SBvtLQTmioHwWXfg0zC2raMUm/UBzRlMId5t 7Asp3nVyA0MhYxD9i4+icoDEuZxioJhZWUGaGguN9+TJDtCcZY0jVpOQvVI8VMdJEFe473 aeJySqtFB2kUDdtU6iSZ3KOAZOv4qER3QaYlGBaDFv97XGkJQd+h+XbExOwxF5dgW11wOZ kljG5h4IaTgdOMWRjf/NvUYEZIF0eRU/xIJxmM61v1PQ3bcn8WhiUE7gOjOK6OOkbmQxia qzOV1AuWVOvO4Zj3V80pksHk5tDS1OYNgjzNYAN4mrVtLI8ybwTZKLFv1GHDMw== From: "Dragan Simic" In-Reply-To: Content-Type: text/plain; charset="utf-8" References: Date: Sat, 15 Nov 2025 10:24:49 +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 1/3] =?utf-8?q?PCI=3A?==?utf-8?q?_rockchip=3A?= warn of danger of =?utf-8?q?5=2E0?= GT/s speeds 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_012455_274063_842BA3F5 X-CRM114-Status: GOOD ( 13.91 ) 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: > Shawn Lin from Rockchip has reiterated that there may be danger in us= ing > their PCIe with 5.0 GT/s speeds. Warn the user if they make a DT chan= ge > from the default and at the same time, drive at 2.5 GT/s only, in cas= e > the DT max-link-speed property is invalid or inexistent. >=20 > Fixes: 956cd99b35a8 ("PCI: rockchip: Separate common code from RC dri= ver") > 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.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) >=20 > diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/con= troller/pcie-rockchip.c > index 0f88da378805..ed67886a6d43 100644 > --- a/drivers/pci/controller/pcie-rockchip.c > +++ b/drivers/pci/controller/pcie-rockchip.c > @@ -66,8 +66,12 @@ int rockchip=5Fpcie=5Fparse=5Fdt(struct rockchip=5F= pcie *rockchip) > } > =20 > rockchip->link=5Fgen =3D of=5Fpci=5Fget=5Fmax=5Flink=5Fspeed(node); > - if (rockchip->link=5Fgen < 0 || rockchip->link=5Fgen > 2) > - rockchip->link=5Fgen =3D 2; > + if (rockchip->link=5Fgen < 0 || rockchip->link=5Fgen > 2) { > + rockchip->link=5Fgen =3D 1; > + dev=5Fwarn(dev, "invalid max-link-speed, set to 2.5 GT/s\n"); > + } > + else if (rockchip->link=5Fgen =3D=3D 2) > + dev=5Fwarn(dev, "5.0 GT/s may lead to catastrophic failure\n"); > =20 > for (i =3D 0; i < ROCKCHIP=5FNUM=5FPM=5FRSTS; i++) > rockchip->pm=5Frsts[i].id =3D rockchip=5Fpci=5Fpm=5Frsts[i]; Looking good to me, thanks for this patch! People often declare PCIe Gen2 on RK3399-based boards as "works for me", which actually happens very often, but such simple evaluations cannot be taken as a proof of Gen2 correctness. Furthermore, RK3399's internal interconnects limit the effective I/O speed of PCIe transfers already, so switching to PCIe Gen1 actually doesn't result in some large I/O performance penalties. With all that in mind, please feel free to include Reviewed-by: Dragan Simic