From: "Krzysztof Wilczyński" <kw@linux.com>
To: "David E. Box" <david.e.box@linux.intel.com>
Cc: nirmal.patel@linux.intel.com, jonathan.derrick@linux.dev,
lorenzo.pieralisi@arm.com, robh@kernel.org, bhelgaas@google.com,
michael.a.bottini@linux.intel.com, rafael@kernel.org,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] PCI/ASPM: Add ASPM BIOS override function
Date: Tue, 30 Nov 2021 09:03:23 +0100 [thread overview]
Message-ID: <YaXay7MkIybYz4uI@rocinante> (raw)
In-Reply-To: <20211120015756.1396263-1-david.e.box@linux.intel.com>
Hi David,
[...]
> @@ -562,11 +562,13 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev);
> void pcie_aspm_exit_link_state(struct pci_dev *pdev);
> void pcie_aspm_pm_state_change(struct pci_dev *pdev);
> void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
> +void pcie_aspm_policy_override(struct pci_dev *dev);
> #else
> static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { }
> static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { }
> static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }
> static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }
> +static inline void pcie_aspm_policy_override(struct pci_dev *dev) {}
> #endif
A small nitpick, and a slight OCD on my part, so feel free to ignore this,
of course: a missing space between curly brackets, to keep things aligned
with previous definitions.
> @@ -1140,6 +1140,24 @@ int pci_disable_link_state(struct pci_dev *pdev, int state)
> }
> EXPORT_SYMBOL(pci_disable_link_state);
>
> +void pcie_aspm_policy_override(struct pci_dev *pdev)
> +{
> + struct pcie_link_state *link = pcie_aspm_get_link(pdev);
> +
> + down_read(&pci_bus_sem);
> + mutex_lock(&aspm_lock);
> +
> + if (link) {
> + link->aspm_default = ASPM_STATE_ALL;
> + pcie_config_aspm_link(link, policy_to_aspm_state(link));
> + pcie_set_clkpm(link, policy_to_clkpm_state(link));
> + }
> +
> + mutex_unlock(&aspm_lock);
> + up_read(&pci_bus_sem);
> +}
> +EXPORT_SYMBOL(pcie_aspm_policy_override);
What about the following version where if we have no link (albeit, I am not
sure how often this is going to be the case?) then we don't even attempt to
get a hold on the lock and such:
void pcie_aspm_policy_override(struct pci_dev *pdev)
{
struct pcie_link_state *link = pcie_aspm_get_link(pdev);
if (!link)
return;
down_read(&pci_bus_sem);
mutex_lock(&aspm_lock);
link->aspm_default = ASPM_STATE_ALL;
pcie_config_aspm_link(link, policy_to_aspm_state(link));
pcie_set_clkpm(link, policy_to_clkpm_state(link));
mutex_unlock(&aspm_lock);
up_read(&pci_bus_sem);
}
What do you think? Would this make sense?
Krzysztof
prev parent reply other threads:[~2021-11-30 8:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-20 1:57 [PATCH 1/2] PCI/ASPM: Add ASPM BIOS override function David E. Box
2021-11-20 1:57 ` [PATCH 2/2] PCI: vmd: Override ASPM on TGL/ADL VMD devices David E. Box
2021-11-20 5:13 ` kernel test robot
2021-11-20 16:35 ` kernel test robot
2021-11-30 8:03 ` Krzysztof Wilczyński [this message]
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=YaXay7MkIybYz4uI@rocinante \
--to=kw@linux.com \
--cc=bhelgaas@google.com \
--cc=david.e.box@linux.intel.com \
--cc=jonathan.derrick@linux.dev \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=michael.a.bottini@linux.intel.com \
--cc=nirmal.patel@linux.intel.com \
--cc=rafael@kernel.org \
--cc=robh@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