mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-06 02:50:49 +09:00
ef56d0e0b7
commit8ef0217227upstream. If a PCI bridge is suspended to D3cold upon entering system sleep, resuming it entails a Fundamental Reset per PCIe r6.0 sec 5.8. The delay prescribed after a Fundamental Reset in PCIe r6.0 sec 6.6.1 is sought to be observed by: pci_pm_resume_noirq() pci_pm_bridge_power_up_actions() pci_bridge_wait_for_secondary_bus() However, pci_bridge_wait_for_secondary_bus() bails out if the bridge_d3 flag is not set. That flag indicates whether a bridge is allowed to suspend to D3cold at *runtime*. Hence *no* delay is observed on resume from system sleep if runtime D3cold is forbidden. That doesn't make any sense, so drop the bridge_d3 check from pci_bridge_wait_for_secondary_bus(). The purpose of the bridge_d3 check was probably to avoid delays if a bridge remained in D0 during suspend. However the sole caller of pci_bridge_wait_for_secondary_bus(), pci_pm_bridge_power_up_actions(), is only invoked if the previous power state was D3cold. Hence the additional bridge_d3 check seems superfluous. Fixes:ad9001f2f4("PCI/PM: Add missing link delays required by the PCIe spec") Link: https://lore.kernel.org/r/eb37fa345285ec8bacabbf06b020b803f77bdd3d.1673769517.git.lukas@wunner.de Tested-by: Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.