From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ua1-f46.google.com (mail-ua1-f46.google.com [209.85.222.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 986DD4C81 for ; Thu, 26 Feb 2026 00:18:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772065137; cv=none; b=pfzZtJ6mNC3xTBNlwY0WMsaneoN0MsLGK0d58jl/gl+wYEa043OICWkj2yxifLTNEW780dLoaEjBBwqJ8bj2y/39248sgAdY8c1cIRbHDKFIxohD++Fs8Y2F+kvcLU1gMzSz/c5Ng6V0LOpLUCx7LDK+OmDlTnQfUbgFj+a1EOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772065137; c=relaxed/simple; bh=5ETDtDJCz2/lDp8wvDlrZGEs/wjF93z8VEpvhKcaLkE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GzOo5CbCvDrI3tcq06hE4b/OOu0mMqxU1olWha/7n+FaucBva4mmW0K3XRX0VlJpTikKhHl+F/8hiee/KkF9Gx+HXt8IIkaIdy5YXwEVkkgXr+m8oYPZN+hunbZZ7Mk7IpsJLbRlbp3da/O9HB5MAQc8eb4+VLX221JxUoygBQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=dJicNbmb; arc=none smtp.client-ip=209.85.222.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dJicNbmb" Received: by mail-ua1-f46.google.com with SMTP id a1e0cc1a2514c-94de4f5531eso93319241.0 for ; Wed, 25 Feb 2026 16:18:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1772065135; x=1772669935; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=aT/CuULkbwm3ZtLWPS1iAQDnaaV5hiK+YKdLvwy3we0=; b=dJicNbmbFzjln2wLRpX46qfbBM2n2n/wFFl6homgO7RZ5MEP4YJ7YW++eNjF5e496y UlcNYPDrVzKoWc63TO9lZ7v+RnkaRZCW3LWVpR3+RrkTYkriOWaWwSK9DWXWqnq5HQGR BdEEXA4Fm1j6IJjLw1/lJy7lce0GKVZKXdZhYRX/ApHev61mbPu2TGlgrRFSaw2S6Kws THVjqYINfgzxJnLxQRJbIMt80wSdUxAgel77RPqvCOaK5X/jfq9xyRMyB6DmbHfTzgBQ dLrhCQV5eRWfj6PJBE2hGDLnIZPgpz8zZ41l1TWYwHj1wa2sl2B0Wm3jGjdgIosqNX72 wQiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772065135; x=1772669935; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=aT/CuULkbwm3ZtLWPS1iAQDnaaV5hiK+YKdLvwy3we0=; b=IAOZrRXcRdRYnyiJFIwV1khCch9fpLLHIl1PWu/10TrC3oN7AFXfuL6XeY6PFkzTSQ 2kd5hEPsgA2D2XvQR8ekrmEBLsjuh4zhv1pVF3fjCOfd68EjrJ7EpSN70Xj4FXEeQHpe 7dRpDFou9tI3ek4fZHC9ctnMNDiztJiS81kX0SnHEnRCR0cnlWUiZd++7J907/TgQx5M pfu9aQ+cTba3IsQCuMbNRuQcFjVBsJCVWcjB9NOLJd02GKYrpboJC2qv+O2WWZjpsnje rURck0XTsYGK3ra/S1Vq8OsdR4so15pdY3TvkBEgK+yNk/etS/VoD2ybo/VMYYVUjf8x EALA== X-Forwarded-Encrypted: i=1; AJvYcCW935wzy8wz8Eyr+fiKV4iUHJTgcxN5cwaSoIuIguHCl0O/8x3aDhMx9zVS8oVJftgxGGAdOYM9nY8VUKU=@vger.kernel.org X-Gm-Message-State: AOJu0YzU1KJ7UeY9gpoctT7B1H4emmLgcJEr/ofDNIjUSk5x+Cd/zLiu VW/GXpUZtw6nj6xoAtv6ERbJuWXrjpjThmHJiV/TQdVGuDjkzTB0Bb1p X-Gm-Gg: ATEYQzwfk/qOOvnNzgyNO6AH+oF4/LoXNykJmOjKh7ibZKTBkPbdAZUy14SVRh/OWOW fQYI102NvR6r3Lmllm+puQ6qO9jazQxSdSrOewx4drw9isdtr4F8vg1CPxLO7p0jkbHMsdopo2t dqf6mQosdyVKbD8wGf4/8FE7pO7bPBVy4ux/z06r22jqW/PqdOL67NlJiGDbVXD0nZUW6YeZPOv 661f4OYKZpKVN9YkGLUSyxD0mKWa+SLktKIwmvc0mYLRaD1Jf8ThVtinJTb8PpWtBnsMYZpdUWf jpiNihwzgjMluijYWcZDxFNVfhHIBFzTKYoBJ10CIcIj7BFAfoXMx8ZzWbanqq0t8ro04IMewo2 EKTk2czXx9sQD3IaB+l5Y5MFuf9xstI406tcYt5J5vnEMoujFCm2FuPRu7QgR99wM4WBI0hIVwQ BzxIQP34+cag== X-Received: by 2002:a05:6102:358d:b0:5db:3bbf:8e62 with SMTP id ada2fe7eead31-5feb2e60d7dmr7045155137.1.1772065135433; Wed, 25 Feb 2026 16:18:55 -0800 (PST) Received: from geday ([2804:7f2:800b:f14d::dead:c001]) by smtp.gmail.com with ESMTPSA id ada2fe7eead31-5ff1ea6ea19sm612107137.12.2026.02.25.16.18.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Feb 2026 16:18:54 -0800 (PST) Date: Wed, 25 Feb 2026 21:18:48 -0300 From: Geraldo Nascimento To: Bjorn Helgaas Cc: Shawn Lin , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , Bjorn Helgaas , Heiko Stuebner , Dragan Simic , linux-rockchip@lists.infradead.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] PCI: rockchip-host: comment danger of 5.0 GT/s speed Message-ID: References: <8db835ffe384db63ee598a203751b298ad1cc267.1772057799.git.geraldogabriel@gmail.com> <20260226001229.GA3794668@bhelgaas> 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: <20260226001229.GA3794668@bhelgaas> On Wed, Feb 25, 2026 at 06:12:29PM -0600, Bjorn Helgaas wrote: > On Wed, Feb 25, 2026 at 07:27:44PM -0300, 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 this risk of > > "catastrophic failure" and discouraging end-users from forcing > > higher speed. > > A comment in the code might be useful but doesn't discourage end > users. Hi Bjorn, thanks for the quick review. > > > Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21b@rock-chips.com/ > > Cc: stable@vger.kernel.org > > Reported-by: Dragan Simic > > Reported-by: Shawn Lin > > Reviewed-by: Dragan Simic > > Signed-off-by: Geraldo Nascimento > > --- > > drivers/pci/controller/pcie-rockchip-host.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c > > index ee1822ca01db..4faf3e29b7d5 100644 > > --- a/drivers/pci/controller/pcie-rockchip-host.c > > +++ b/drivers/pci/controller/pcie-rockchip-host.c > > @@ -332,6 +332,10 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip) > > /* > > * Enable retrain for gen2. This should be configured only after > > * gen1 finished. > > + * > > + * Dangerous and may lead to "catastrophic failure", with data loss > > + * or worse! > > + * > > Wrap comment to fit in 80 columns like the rest of the file. > > Remove spurious blank line at end. > > This should probably be squashed with the first patch; I don't see the > benefit of having them separate. > > Why don't we just remove this whole "link_gen == 2" block? If we > don't want to use it, there's no point in keeping the code. Yes, I think I'll go with this second option and remove the code block outright. Thanks, Geraldo Nascimento > > > */ > > status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_CR + PCI_EXP_LNKCTL2); > > status &= ~PCI_EXP_LNKCTL2_TLS; > > -- > > 2.52.0 > > > > > > _______________________________________________ > > Linux-rockchip mailing list > > Linux-rockchip@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-rockchip