kernel/linux.git/drivers/pci/controller, branch v6.1.175

PCI: tegra194: Allow system suspend when the Endpoint link is not up

2026-06-01T15:39:14+00:00

[ Upstream commit c76f8eae7d4695b1176c4ea5eb93c17e16a20272 ] Host software initiates the L2 sequence. PCIe link is kept in L2 state during suspend. If Endpoint mode is enabled and the link is up, the software cannot proceed with suspend. However, when the PCIe Endpoint driver is probed, but the PCIe link is not up, Tegra can go into suspend state. So, allow system to suspend in this case. Fixes: de2bbf2b71bb ("PCI: tegra194: Don't allow suspend when Tegra PCIe is in EP mode") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Reviewed-by: Vidya Sagar Link: https://patch.msgid.link/20260324190755.1094879-10-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Disable direct speed change for Endpoint mode

2026-06-01T15:39:13+00:00

[ Upstream commit 976f6763f57970388bcd7118931f33f447916927 ] Pre-silicon simulation showed the controller operating in Endpoint mode initiating link speed change after completing Secondary Bus Reset. Ideally, the Root Port or the Switch Downstream Port should initiate the link speed change post SBR, not the Endpoint. So, as per the hardware team recommendation, disable direct speed change for the Endpoint mode to prevent it from initiating speed change after the physical layer link is up at Gen1, leaving speed change ownership with the host. Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy [mani: commit log] Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Reviewed-by: Vidya Sagar Link: https://patch.msgid.link/20260324190755.1094879-8-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Use devm_gpiod_get_optional() to parse "nvidia,refclk-select"

2026-06-01T15:39:13+00:00

[ Upstream commit f62bc7917de1374dce86a852ffba8baf9cb7a56a ] The GPIO DT property "nvidia,refclk-select", to select the PCIe reference clock is optional. Use devm_gpiod_get_optional() to get it. Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Reviewed-by: Vidya Sagar Link: https://patch.msgid.link/20260324190755.1094879-7-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Disable PERST# IRQ only in Endpoint mode

2026-06-01T15:39:13+00:00

[ Upstream commit 40658a31b6e134169c648041efc84944c4c71dcd ] The PERST# GPIO interrupt is only registered when the controller is operating in Endpoint mode. In Root Port mode, the PERST# GPIO is configured as an output to control downstream devices, and no interrupt is registered for it. Currently, tegra_pcie_dw_stop_link() unconditionally calls disable_irq() on pex_rst_irq, which causes issues in Root Port mode where this IRQ is not registered. Fix this by only disabling the PERST# IRQ when operating in Endpoint mode, where the interrupt is actually registered and used to detect PERST# assertion/deassertion from the host. Fixes: c57247f940e8 ("PCI: tegra: Add support for PCIe endpoint mode in Tegra194") Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Reviewed-by: Vidya Sagar Link: https://patch.msgid.link/20260324190755.1094879-6-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Don't force the device into the D0 state before L2

2026-06-01T15:39:13+00:00

[ Upstream commit 71d9f67701e1affc82d18ca88ae798c5361beddf ] As per PCIe CEM r6.0, sec 2.3, the PCIe Endpoint device should be in D3cold to assert WAKE# pin. The previous workaround that forced downstream devices to D0 before taking the link to L2 cited PCIe r4.0, sec 5.2, "Link State Power Management"; however, that spec does not explicitly require putting the device into D0 and only indicates that power removal may be initiated without transitioning to D3hot. Remove the D0 workaround so that Endpoint devices can use wake functionality (WAKE# from D3). With some Endpoints the link may not enter L2 when they remain in D3, but the Root Port continues with the usual flow after PME timeout, so there is no functional issue. Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Vidya Sagar Reviewed-by: Jon Hunter Link: https://patch.msgid.link/20260324190755.1094879-5-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Rename 'root_bus' to 'root_port_bus' in tegra_pcie_downstream_dev_to_D0()

2026-06-01T15:39:13+00:00

[ Upstream commit e1bd928479fb1fa60e9034b0fdb1ab9f3fa92f33 ] In tegra_pcie_downstream_dev_to_D0(), PCI devices are transitioned to D0 state. For iterating over the devices, first the downstream bus of the Root Port is searched from the root bus. But the name of the variable that holds the Root Port downstream bus is named as 'root_bus', which is wrong. Rename the variable to 'root_port_bus'. Also, move the comment on 'bringing the devices to D0' to where the state is set exactly. Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20250922081057.15209-1-mani@kernel.org Stable-dep-of: 71d9f67701e1 ("PCI: tegra194: Don't force the device into the D0 state before L2") Signed-off-by: Sasha Levin

PCI: tegra194: Disable LTSSM after transition to Detect on surprise link down

2026-06-01T15:39:13+00:00

[ Upstream commit 9fa0c242f8d7acf1b124d4462d18f4023573ac1c ] After the link reaches a Detect-related LTSSM state, disable LTSSM so it does not keep toggling between Polling and Detect. Do this by polling for the Detect state first, then clearing APPL_CTRL_LTSSM_EN in both tegra_pcie_dw_pme_turnoff() and pex_ep_event_pex_rst_assert(). Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Link: https://patch.msgid.link/20260324190755.1094879-4-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Increase LTSSM poll time on surprise link down

2026-06-01T15:39:13+00:00

[ Upstream commit 74dd8efe4d6cead433162147333af989a568aac7 ] On surprise link down, LTSSM state transits from L0 -> Recovery.RcvrLock -> Recovery.RcvrSpeed -> Gen1 Recovery.RcvrLock -> Detect. Recovery.RcvrLock and Recovery.RcvrSpeed transit times are 24 ms and 48 ms respectively, so the total time from L0 to Detect is ~96 ms. Increase the poll timeout to 120 ms to account for this. While at it, add LTSSM state defines for Detect-related states and use them in the poll condition. Use readl_poll_timeout() instead of readl_poll_timeout_atomic() in tegra_pcie_dw_pme_turnoff() since that path runs in non-atomic context. Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Link: https://patch.msgid.link/20260324190755.1094879-3-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: tegra194: Fix polling delay for L2 state

2026-06-01T15:39:13+00:00

[ Upstream commit adaffed907f14f954096555665ad6af2ae724d83 ] As per PCIe r7.0, sec 5.3.3.2.1, after sending PME_Turn_Off message, Root Port should wait for 1-10 msec for PME_TO_Ack message. Currently, driver is polling for 10 msec with 1 usec delay which is aggressive. Use existing macro PCIE_PME_TO_L2_TIMEOUT_US to poll for 10 msec with 1 msec delay. Since this function is used in non-atomic context only, use non-atomic poll function. Fixes: 56e15a238d92 ("PCI: tegra: Add Tegra194 PCIe support") Signed-off-by: Vidya Sagar Signed-off-by: Manikanta Maddireddy Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Jon Hunter Reviewed-by: Jon Hunter Link: https://patch.msgid.link/20260324190755.1094879-2-mmaddireddy@nvidia.com Signed-off-by: Sasha Levin

PCI: mediatek-gen3: Prevent leaking IRQ domains when IRQ not found

2026-06-01T15:39:12+00:00

[ Upstream commit 5573c44cb3fd01a9f62d569ae9ac870ef5f0e0ba ] In mtk_pcie_setup_irq(), the IRQ domains are allocated before the controller's IRQ is fetched. If the latter fails, the function directly returns an error, without cleaning up the allocated domains. Hence, reverse the order so that the IRQ domains are allocated after the controller's IRQ is found. This was flagged by Sashiko during a review of "[PATCH v6 0/7] PCI: mediatek-gen3: add power control support". Fixes: 814cceebba9b ("PCI: mediatek-gen3: Add INTx support") Signed-off-by: Chen-Yu Tsai Signed-off-by: Manivannan Sadhasivam Link: https://sashiko.dev/#/patchset/20260324052002.4072430-1-wenst%40chromium.org Link: https://patch.msgid.link/20260324093542.18523-1-wenst@chromium.org Signed-off-by: Sasha Levin