From: Rob Herring <robh@kernel.org>
To: Vidya Sagar <vidyas@nvidia.com>
Cc: lpieralisi@kernel.org, kw@linux.com, bhelgaas@google.com,
krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
will@kernel.org, frowand.list@gmail.com,
linux-pci@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, treding@nvidia.com,
jonathanh@nvidia.com, kthota@nvidia.com, mmaddireddy@nvidia.com,
sagar.tv@gmail.com
Subject: Re: [PATCH V2 1/2] dt-bindings: Add PCIe "preserve-boot-config" property
Date: Fri, 12 Jan 2024 08:33:20 -0600 [thread overview]
Message-ID: <20240112143320.GA3143039-robh@kernel.org> (raw)
In-Reply-To: <20240110030725.710547-2-vidyas@nvidia.com>
On Wed, Jan 10, 2024 at 08:37:24AM +0530, Vidya Sagar wrote:
> The existing "linux,pci-probe-only" property applies at a system level
> and it is not possible to selectively convey individual host bridge's
> requirement w.r.t preserving the boot configuration done by the platform
> firmware to the kernel. "preserve-boot-config" addresses that concern
> and can be used to preserve the boot configuration for host bridges
> selectivey.
>
> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
> ---
> V2:
> * None
>
> Documentation/devicetree/bindings/pci/pci.txt | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> index 6a8f2874a24d..0a5ff998cbe8 100644
> --- a/Documentation/devicetree/bindings/pci/pci.txt
> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> @@ -32,6 +32,10 @@ driver implementation may support the following properties:
> root port to downstream device and host bridge drivers can do programming
> which depends on CLKREQ signal existence. For example, programming root port
> not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal.
> +- preserve-boot-config:
> + If present this property specifies that this host bridge is already
> + configured by the platform firmware and the OS doesn't need to reconfigure
> + it again.
Anything new must be a schema.
Don't create something new to workaround the problem. Extend the
existing support. For this, make "linux,pci-probe-only" allowed in host
bridge nodes. Yeah, there's the issue that this property sets a global
flag, but I'd imagine the PCI maintainers would agree that some flags
should/could be per bus.
Rob
next prev parent reply other threads:[~2024-01-12 14:33 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-10 3:07 [PATCH V2 0/2] Add support to preserve boot config in the DT flow Vidya Sagar
2024-01-10 3:07 ` [PATCH V2 1/2] dt-bindings: Add PCIe "preserve-boot-config" property Vidya Sagar
2024-01-12 14:33 ` Rob Herring [this message]
2024-01-10 3:07 ` [PATCH V2 2/2] PCI: Add support for " Vidya Sagar
2024-01-12 16:58 ` Bjorn Helgaas
2024-01-15 14:32 ` Vidya Sagar
2024-01-16 16:55 ` Rob Herring
2024-01-19 17:31 ` Bjorn Helgaas
2024-01-12 16:59 ` Bjorn Helgaas
2024-02-22 12:41 ` [PATCH V3] PCI: Add support for preserving boot configuration Vidya Sagar
2024-02-22 17:06 ` Bjorn Helgaas
2024-02-22 21:18 ` Vidya Sagar
2024-02-22 22:08 ` Bjorn Helgaas
2024-02-23 8:00 ` [PATCH V4] " Vidya Sagar
2024-03-05 14:10 ` Rob Herring
2024-03-05 14:24 ` Rob Herring
2024-04-01 7:50 ` [PATCH V5] " Vidya Sagar
2024-04-02 16:01 ` Rob Herring
2024-04-10 7:44 ` Vidya Sagar
2024-04-10 20:50 ` Bjorn Helgaas
2024-04-18 17:31 ` Vidya Sagar
2024-04-18 17:40 ` [PATCH V6] " Vidya Sagar
2024-04-21 19:03 ` Bjorn Helgaas
2024-04-21 19:09 ` [PATCH v7-incomplete 0/3] " Bjorn Helgaas
2024-04-21 19:09 ` [PATCH v7-incomplete 1/3] PCI: Move PRESERVE_BOOT_CONFIG _DSM evaluation to pci_register_host_bridge() Bjorn Helgaas
2024-04-22 7:45 ` Andy Shevchenko
2024-04-21 19:09 ` [PATCH v7-incomplete 2/3] PCI: of: Add of_pci_preserve_config() for per-host bridge support Bjorn Helgaas
2024-04-21 19:09 ` [PATCH v7-incomplete 3/3] PCI: Unify ACPI and DT 'preserve config' support Bjorn Helgaas
2024-04-22 7:43 ` Andy Shevchenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240112143320.GA3143039-robh@kernel.org \
--to=robh@kernel.org \
--cc=bhelgaas@google.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=frowand.list@gmail.com \
--cc=jonathanh@nvidia.com \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=kthota@nvidia.com \
--cc=kw@linux.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=lpieralisi@kernel.org \
--cc=mmaddireddy@nvidia.com \
--cc=sagar.tv@gmail.com \
--cc=treding@nvidia.com \
--cc=vidyas@nvidia.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).