kernel/git/next/linux-next.git/drivers/pci/pcie, branch master

PCI/ASPM: Return enabled ASPM states from pcie_aspm_enabled() API

2026-09-14T20:54:00+00:00

pcie_aspm_enabled() returns 'pcie_link_state::aspm_enabled' parameter which contains the enabled states. But the API currently returns the 'bool' type which is used by the callers to decide if ASPM is enabled or not. To allow the future callers to also make use of the enabled ASPM states, return the actual type of 'pcie_link_state::aspm_enabled' parameter, 'u32'. Existing callers can still treat the return value as a 'bool' as the C11 standard guarantees the behavior (this API relied on the same behavior before as well). Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260708-pci-aspm-fix-v3-5-6bd72451746e@kernel.org

PCI/ASPM: Improve kernel-doc for pci_{enable,disable}_link_state*() APIs

2026-09-14T20:53:42+00:00

Add kernel-doc for pci_disable_link_state_locked() API and fix the kernel-doc for pci_disable_link_state() API. Also convert the kernel-doc of pci_enable_link_state() and pci_enable_link_state_locked() APIs to the standard format and mention that pci_force_enable_link_state() should be used to re-enable the states disabled by pci_disable_link_state(). Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260708-pci-aspm-fix-v3-4-6bd72451746e@kernel.org

PCI/ASPM: Transition the device to D0 (if required) when enabling ASPM link states

2026-09-14T20:53:17+00:00

Per PCIe spec r6.0, sec 5.5.4: If setting either or both of the enable bits for PCI-PM L1 PM Substates, both ports must be configured as described in this section while in D0. Currently, the callers of pci_enable_link_state_locked() (vmd, pcie-qcom) transition the device to D0 themselves before enabling the link state. But this is easy to get wrong and has to be duplicated by every caller. Move the D0 transition into the shared __pci_enable_link_state() helper so that all three APIs pci_enable_link_state(), pci_enable_link_state_locked() and pci_force_enable_link_state() perform it, and only when the PCI-PM L1 PM Substates are getting enabled. Now that the helper handles the transition, drop the redundant D0 transition from the vmd and pcie-qcom callers. Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260708-pci-aspm-fix-v3-3-6bd72451746e@kernel.org

PCI/ASPM: Add pci_force_enable_link_state() API

2026-09-14T20:53:02+00:00

pci_enable_link_state() and pci_enable_link_state_locked() APIs only enable the ASPM states that were not previously disabled via pci_disable_link_state*() API or blacklisted during init (e.g. the pre-1.1 device blacklist, which is only meant to be overridden with 'pcie_aspm=force'). This is an intentional behavior as these APIs must not silently re-enable states that were deliberately disabled, since doing so could enable ASPM on a link where it is known to be unsafe. However, some drivers (e.g. the atheros WLAN drivers) save the currently enabled ASPM states, disable all ASPM states before firmware download, and then try to restore exactly the states that were enabled before. Restoring those states requires re-enabling states that were just disabled via pci_disable_link_state() API. But, this cannot be achieved using the existing APIs. Hence, add pci_force_enable_link_state() API for such callers. Unlike pci_enable_link_state(), it re-enables the requested states even if they were previously disabled via pci_disable_link_state() or disabled during init. The caller is therefore responsible for only enabling states the device actually supports, typically the ones previously reported by pcie_aspm_enabled(). This API is implemented by adding a 'force' parameter to the shared __pci_enable_link_state() helper. When 'force' is true, the requested states are cleared from 'link->aspm_disable' before enabling. Suggested-by: Ilpo Järvinen Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260708-pci-aspm-fix-v3-2-6bd72451746e@kernel.org

PCI/ASPM: Always disable ASPM when driver requests it

2026-09-14T20:52:37+00:00

PCI core/ASPM service driver allows controlling ASPM state through pci_disable_link_state() API. It was decided earlier (see the Link below), to not allow ASPM changes when OS does not have control over it but only log a warning about the problem 'commit 2add0ec14c25 ("PCI/ASPM: Warn when driver asks to disable ASPM, but we can't do it")'. A number of drivers have added workarounds to force ASPM off with own writes into the Link Control Register (some even with comments explaining why PCI core does not disable it under some circumstances). According to the comments, some drivers require ASPM to be off for reliable operation. Having custom ASPM handling in drivers is problematic because the state kept in the ASPM service driver is not updated by the changes made outside the link state management API. As the first step to address this issue, make pci_disable_link_state() to unconditionally disable ASPM so the motivation for drivers to come up with custom ASPM handling code is eliminated. To fully take advantage of the ASPM handling core provides, the drivers that need to quirk ASPM have to be altered depend on PCIEASPM and the custom ASPM code is removed. This is to be done separately. As PCIEASPM is already behind EXPERT, it should be no problem to limit disabling it for configurations that do not require touching ASPM. Make pci_disable_link_state() function comment to comply kerneldoc formatting while changing the description. Link: https://lore.kernel.org/all/CANUX_P3F5YhbZX3WGU-j1AGpbXb_T9Bis2ErhvKkFMtDvzatVQ@mail.gmail.com/ Link: https://lore.kernel.org/all/20230511131441.45704-1-ilpo.jarvinen@linux.intel.com/ Signed-off-by: Ilpo Järvinen [mani: commit message fixup] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20260708-pci-aspm-fix-v3-1-6bd72451746e@kernel.org

Merge branch 'pci/controller/dwc'

2026-08-21T21:40:41+00:00

- Factor pcie_valid_speed() and pci_bus_speed2lnkctl2() out of bwctrl so they can be shared by the DWC core (Hans Zhang) - Flush MSI writes from endpoint before unmapping the iATU, as we already do for MSI-X writes (Niklas Cassel) - Unmap MSI iATU window before mapping MSI-X window, to avoid a subsequent MSI write using a disabled aperture and losing the interrupt (Niklas Cassel) - Change endpoint .pre_init() and .init() callbacks to return errors and handle them (Marek Vasut) * pci/controller/dwc: PCI: dwc: Handle return value from endpoint .pre_init callback PCI: dwc: Handle return value from endpoint .init callback PCI: dwc: ep: Fix unmap potentially unmapping the wrong iATU PCI: dwc: ep: Flush cached MSI write before unmapping the iATU PCI: dwc: Use common speed conversion function PCI: Move pci_bus_speed2lnkctl2() to public header PCI: Add public pcie_valid_speed() for shared validation

Merge branch 'pci/controller/root-port-reset'

2026-08-21T21:40:40+00:00

* pci/controller/root-port-reset: misc: pci_endpoint_test: Add AER error handlers PCI: dw-rockchip: Implement .reset_root_port() and use for link down PCI: qcom: Implement .reset_root_port() and use for link down PCI: host-common: Add link down handling for Root Ports PCI/ERR: Add support for resetting the Root Ports in a platform-specific way PCI: dwc: ep: Clear MSI iATU mapping in dw_pcie_ep_cleanup()

Merge branch 'pci/portdrv'

2026-08-21T21:40:36+00:00

- Allow probing even without child services so it can do power management (Brian Norris) * pci/portdrv: PCI/portdrv: Allow probing even without child services

Merge branch 'pci/dpc'

2026-08-21T21:40:34+00:00

- Allow DPC on all Downstream Ports, not just Root Ports, when OS controls AER (Darshit Shah) * pci/dpc: PCI/DPC: Allow DPC on all Downstream Ports when OS controls AER

Merge branch 'pci/aspm'

2026-08-21T21:40:33+00:00

- Avoid L0s for Realtek RTS525A, where it causes an AER interrupt storm (Max Lee) - Program the same ASPM Control values for every function of multi-function devices, as recommended by the PCIe spec (Krishna Chaitanya Chundru) - Avoid ASPM L0s, L1, and L1 PM Substates based on 'aspm-no-l0s', 'aspm-no-l1' [1], and 'aspm-no-l1ss' DT properties (Krishna Chaitanya Chundru) * pci/aspm: PCI/ASPM: Mask ASPM states based on Devicetree properties PCI/ASPM: Disable/restore ASPM on every function for multi-function devices PCI/ASPM: Use pcie_capability_clear_and_set_word() for ASPM disable/restore PCI/ASPM: Avoid L0s for Realtek RTS525A