From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail1.manjaro.org (mail1.manjaro.org [142.132.176.110]) (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 84DAE219E8D; Sat, 15 Nov 2025 10:01:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=142.132.176.110 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763200888; cv=none; b=Irm4CACWT/tIr+1VUTPPOFzXcPfQpA8sVwdGhsZtGLfp9QxtTE/QpZTDWUQSCQWv5np85NFYVUIUySucn+zQ+So9SxZwXzaTFISovjapQnnRFuB2d9jvZEUwsb/8gF4WDCZ2ebhXCvT3yPSST4dN8yCVkFm1jOkE2/Zoj3WGALk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763200888; c=relaxed/simple; bh=HpAHnMhc8Vo2IprEXsmiQzzvRuicic5L/MkbfXbUEkg=; h=From:In-Reply-To:Content-Type:References:Date:Cc:To:MIME-Version: Message-ID:Subject; b=bBxZ3wVaAsl0INy+g9dqQVM2hbTdJW1byuOev9uTqkUAphbCvgP92CK8448v/TUzaBuzkMJKQMhmchXV+EQliC26yOB1FubJRziDaeFqw6MaCabQmAdFQvnFAM9FgSKNGE1/YVTUANCWy7WeMxa5VXDeskPD/JX4R9UcqWR9jS4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org; spf=pass smtp.mailfrom=manjaro.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b=hegVytWf; arc=none smtp.client-ip=142.132.176.110 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manjaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b="hegVytWf" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPA id EE6F040FDD; Sat, 15 Nov 2025 11:01:21 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=dkim; t=1763200883; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=Z8ENjA1O7KsiohjnVwrpnU2+8wRrzBEXFU0FKDVm6Vs=; b=hegVytWfQX3nP/0CyzpqP7bgtbxhgrhc/nnXYmahru2+e65IfcdZ7lDUJ/Dpn6KnIVYtQC z1BZ3sf5qmY/ipJEFBiYcE0WO89reg2fyGeg+4vIjUa4krObEcZg5cnQZtIxVujq1oEwlB 4LqCbXm0lE1Jugf4jhRCpxNcUJpcFDENBBduvKJSbfb3HrAseumPP/4mlByaqRGvXisxMH Vf73esieTh727fByzOtgII2VdPFPvBZ9buAeqA4IesUx+wfisGQBcaaqnTbPw2wWgk4ixG RkOTWnoPNa61s3p8uERWKgliME7y/PRPc/n5Nkmy1S0vnhXYz2yl5HPF1uyJAQ== From: "Dragan Simic" In-Reply-To: Content-Type: text/plain; charset="utf-8" References: Date: Sat, 15 Nov 2025 11:01:21 +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" Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <85d1543b-ea91-5f0f-59d6-e00fcf720938@manjaro.org> 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-Rspamd-Fuzzy: 83c865715b7113a59b93546ee6a88838d4bbcab70d4a53f23333084f29fd2604053233ae0ec2379f12cfaacb3af815deb6e782a9b018734885047e902d4f57c0 On Saturday, November 15, 2025 10:51 CET, Geraldo Nascimento wrote: > On Sat, Nov 15, 2025 at 10:30:49AM +0100, Dragan Simic wrote: > > 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 a= nd > > > discouraging end-users from forcing higher speed through DT chang= es. > > >=20 > > > Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b= 4c21b@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/driver= s/pci/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=5Fp= ort(struct rockchip=5Fpcie *rockchip) > > > /* > > > * Enable retrain for gen2. This should be configured only aft= er > > > * gen1 finished. > > > + * > > > + * According to Rockchip this path is dangerous and may lead t= o > > > + * 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= =5FCR + PCI=5FEXP=5FLNKCTL2); > > > status &=3D ~PCI=5FEXP=5FLNKCTL2=5FTLS; > >=20 > > 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. > >=20 > > Please feel free to include > >=20 > > Reviewed-by: Dragan Simic > > >=20 > I disagree, I think the comment stands. >=20 > Even if we reduce to one line, ex: >=20 > + May cause damage Ah, perhaps I wasn't clear enough, so let me clarify a bit. The comment you added is fine, I just referred to no need for emitting a warning at that point, because it would be emitted already.