From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.2]) (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 48AF82836E; Sun, 18 Jan 2026 13:46:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.2 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768743985; cv=none; b=fixnLIpAlZjcRBahqR63f1Y44oGR5MLfnIfxHdZcN8ZzdH6byx63jNzHvM1Fh8WK2oXJrIGsV+IcxF4WMA+DSreoxNGaQ3JAR7+0gbfAdysYX7QK3ZGZdPP/xxSagmYQh2O01nIqWXW8l4hIM6vCEBXK3KkhHFxUNDDT1DijQSo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768743985; c=relaxed/simple; bh=NrPqJsvZ3LD8pr8ycv5loNTcp4o72ucMHrYcQU+RyC4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fLYxJ57o2wU0XcKoTaHv8pQjWf8JYGvKWdFEBIC9asPo4yXg9Mrb2MXp48Ri99GSKov1OPIHSylG3rtbd9IqMmZ0er30JjCshvLOFMaCOuUwYP4jC8Mha7PfCLIzPn15QzaQoXQHQhJBDKK6qIbwkD5KXkv6e/O/6PNucV/hXxA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=H7EGmAyD; arc=none smtp.client-ip=220.197.31.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="H7EGmAyD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=0bMJsDC1jTMA/bRZ8IOj99a37a8NHcIxgkzTYf0oGOw=; b=H7EGmAyDhgS7fo/8iswScODWoqRLjbnV52fyfvi//23FZZnLEr8VeqLlraz+eT 5ZwVsK3XvNxjpq+5wRZXmF+gw8NjCnwTBz9M1N7+77RuV+53ht8Uo0kAEGhTYE2h 0I3pldtvuSIg7rLZExRSUttck/qRa5fh9aezUwnBeIccs= Received: from [IPV6:240e:b8f:927e:1000:e94b:3b22:e2ce:7986] (unknown []) by gzga-smtp-mtada-g1-2 (Coremail) with SMTP id _____wA32+UO5GxpTBiIGQ--.44891S2; Sun, 18 Jan 2026 21:45:50 +0800 (CST) Message-ID: <6f3b6192-300e-492f-9b07-a8837d6fee5f@163.com> Date: Sun, 18 Jan 2026 21:45:50 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 1/1] PCI: of: Remove max-link-speed generation validation To: bhelgaas@google.com, helgaas@kernel.org Cc: mani@kernel.org, ilpo.jarvinen@linux.intel.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org References: <20251218132036.308094-1-18255117159@163.com> Content-Language: en-US From: Hans Zhang <18255117159@163.com> In-Reply-To: <20251218132036.308094-1-18255117159@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID:_____wA32+UO5GxpTBiIGQ--.44891S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxCw1UXr48Cr48ZF4UuryrtFb_yoW5Ar4kpF WjyryrurW8Wr4fWw4DGa1UZFyjg3Z3WrWktr4rGwnrZw13JF1aqFySgF1YvFnF9FZ5CF47 Z3W2qa17G34jyaDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zR3l1PUUUUU= X-CM-SenderInfo: rpryjkyvrrlimvzbiqqrwthudrp/xtbCwxCyVmls5BCr+wAA3W Hi, Gentle ping. Best regards, Hans On 2025/12/18 21:20, Hans Zhang wrote: > The current implementation of of_pci_get_max_link_speed() validates > max-link-speed property values to be in the range 1~4 (Gen1~Gen4). > However, this creates maintenance overhead as each new PCIe generation > requires updating this validation logic. > > Since device tree binding validation already enforces the allowed > values through the schema, and the callers of this function perform > their own validation checks, this intermediate validation becomes > redundant. > > Furthermore, with upcoming SOCs using Synopsys/Cadence IP requiring > Gen5/Gen6 support, removing this hardcoded check enables seamless > support for future PCIe generations without requiring kernel updates > for each new speed grade. > > Remove the max-link-speed > 4 validation check while retaining the > property existence and non-zero check. This simplifies maintenance > and aligns with the existing validation architecture where DT binding > and driver-level checks provide sufficient validation. > > Signed-off-by: Hans Zhang <18255117159@163.com> > Acked-by: Manivannan Sadhasivam > --- > Changes for v6: > - It'd be good to return the actual errno as of_property_read_u32() can return > -EINVAL, -ENODATA and -EOVERFLOW. (Mani) > > Changes for v5: > https://patchwork.kernel.org/project/linux-pci/patch/20251218125909.305300-1-18255117159@163.com/ > > - Delete the check for speed. (Mani) > > Changes for v4: > https://patchwork.kernel.org/project/linux-pci/patch/20251105134701.182795-1-18255117159@163.com/ > > - Add pcie_max_supported_link_speed.(Ilpo) > > Changes for v3: > https://patchwork.kernel.org/project/linux-pci/patch/20251101164132.14145-1-18255117159@163.com/ > > - Modify the commit message. > - Add Reviewed-by tag. > > Changes for v2: > https://patchwork.kernel.org/project/linux-pci/cover/20250529021026.475861-1-18255117159@163.com/ > - The following files have been deleted: > Documentation/devicetree/bindings/pci/pci.txt > > Update to this file again: > dtschema/schemas/pci/pci-bus-common.yaml > --- > drivers/pci/of.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/pci/of.c b/drivers/pci/of.c > index 3579265f1198..b56fdbcb3d72 100644 > --- a/drivers/pci/of.c > +++ b/drivers/pci/of.c > @@ -888,10 +888,11 @@ bool of_pci_supply_present(struct device_node *np) > int of_pci_get_max_link_speed(struct device_node *node) > { > u32 max_link_speed; > + int ret; > > - if (of_property_read_u32(node, "max-link-speed", &max_link_speed) || > - max_link_speed == 0 || max_link_speed > 4) > - return -EINVAL; > + ret = of_property_read_u32(node, "max-link-speed", &max_link_speed); > + if (ret) > + return ret; > > return max_link_speed; > }