PCI: stm32: Fix LTSSM EP race with start link

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[ Upstream commit fa81d60990 ]

If the host has deasserted PERST# and started link training before the link
is started on EP side, enabling LTSSM before the endpoint registers are
initialized in the perst_irq handler results in probing incorrect values.

Thus, wait for the PERST# level-triggered interrupt to start link training
at the end of initialization and cleanup the stm32_pcie_[start stop]_link
functions.

Fixes: 151f3d29ba ("PCI: stm32-ep: Add PCIe Endpoint support for STM32MP25")
Signed-off-by: Christian Bruel <christian.bruel@foss.st.com>
[mani: added fixes tag]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: wrap line]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20251114-perst_ep-v1-1-e7976317a890@foss.st.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Christian Bruel 2025-11-14 08:45:52 +01:00 • committed by Greg Kroah-Hartman

parent 7b1e3cb207

commit 0e82816b68

1 changed files with 8 additions and 31 deletions

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drivers/pci/controller/dwc/pcie-stm32-ep.c

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