From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
To: "David E. Box" <david.e.box@linux.intel.com>,
nirmal.patel@linux.intel.com, jonathan.derrick@linux.dev,
lorenzo.pieralisi@arm.com, hch@infradead.org, kw@linux.com,
robh@kernel.org, bhelgaas@google.com,
michael.a.bottini@intel.com, rafael@kernel.org,
me@adhityamohan.in
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V10 0/4] Enable PCIe ASPM and LTR on select hardware
Date: Thu, 19 Jan 2023 21:28:45 -0800 [thread overview]
Message-ID: <a374e36b-2da2-c76c-717c-1381b171d75e@linux.intel.com> (raw)
In-Reply-To: <20230120031522.2304439-1-david.e.box@linux.intel.com>
On 1/19/23 7:15 PM, David E. Box wrote:
> This series adds a work around for enabling PCIe ASPM and for setting PCIe
> LTR values on VMD reserved root ports on select platforms. While
> configuration of these capabilities is usually done by BIOS, on these
> platforms these capabilities will not be configured because the ports are
> not visible to BIOS. This was part of an initial design that expected the
> driver to completely handle the ports, including power management. However
> on Linux those ports are still managed by the PCIe core, which has the
> expectation that they adhere to device standards including BIOS
> configuration, leading to this problem.
>
> The target platforms are Tiger Lake, Alder Lake, and Raptor Lake though the
> latter has already implemented support for configuring the LTR values.
> Meteor Lake is expected add BIOS ASPM support, eliminating the future need
> for this work around.
>
> Note, the driver programs the LTRs because BIOS would also normally do this
> for devices that do not set them by default. Without this, SoC power
> management would be blocked on those platform. This SoC specific value is
> the maximum latency required to allow the SoC to enter the deepest power
> state.
>
> This patch addresses the following open bugzillas on VMD enabled laptops
> that cannot enter low power states.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=212355
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=215063
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=213717
>
Looks good to me.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> David E. Box (3):
> PCI: vmd: Use PCI_VDEVICE in device list
> PCI: vmd: Create feature grouping for client products
> PCI: vmd: Add quirk to configure PCIe ASPM and LTR
>
> Michael Bottini (1):
> PCI/ASPM: Add pci_enable_link_state()
>
> drivers/pci/controller/vmd.c | 97 ++++++++++++++++++++++++++----------
> drivers/pci/pcie/aspm.c | 54 ++++++++++++++++++++
> include/linux/pci.h | 7 +++
> 3 files changed, 132 insertions(+), 26 deletions(-)
>
>
> base-commit: 5dc4c995db9eb45f6373a956eb1f69460e69e6d4
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2023-01-20 5:35 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-20 3:15 [PATCH V10 0/4] Enable PCIe ASPM and LTR on select hardware David E. Box
2023-01-20 3:15 ` [PATCH V10 1/4] PCI/ASPM: Add pci_enable_link_state() David E. Box
2023-01-20 3:15 ` [PATCH V10 2/4] PCI: vmd: Use PCI_VDEVICE in device list David E. Box
2023-01-20 3:15 ` [PATCH V10 3/4] PCI: vmd: Create feature grouping for client products David E. Box
2023-01-20 3:15 ` [PATCH V10 4/4] PCI: vmd: Add quirk to configure PCIe ASPM and LTR David E. Box
2023-03-20 22:56 ` Ville Syrjälä
2023-03-21 2:24 ` David E. Box
2023-03-21 12:38 ` Ville Syrjälä
2023-03-21 23:40 ` David E. Box
2023-01-20 5:28 ` Sathyanarayanan Kuppuswamy [this message]
2023-02-02 15:07 ` [PATCH V10 0/4] Enable PCIe ASPM and LTR on select hardware Lorenzo Pieralisi
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