Re: [PATCH v8 4/4] PCI: qcom: Implement shutdown() callback

[sashiko-bot@kernel.org]

> From: Manivannan Sadhasivam <mani@kernel.org>
> 
> PCIe host controllers should bring the link down cleanly before system
> shutdown/reboot proceeds to remove power/clocks from the controller.
> Without this, the link may still be up and endpoints still have
> transactions in flight when power/clocks are cut, which can trip SMMU
> translation faults or NoC protocol errors.
> 
> Reuse dw_pcie_suspend_noirq() in the shutdown path to force the link
> into L2, putting it into D3cold.
> 
> device_shutdown() runs with interrupts enabled, unlike suspend_noirq().
> Mask the chained MSI IRQ(s) and the Global IRQ before tearing down the
> link and clocks/PHY, since a late/spurious interrupt could otherwise
> reach a handler that touches now-unclocked PARF/DBI registers. Use
> dw_pcie_mask_msi() rather than dw_pcie_free_msi() so the MSI IRQ domain
> and the MSI mappings held by downstream devices (which device_shutdown()
> does not remove) are left intact.
> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261107-shutdown-v8-0-bf607c6429b0@oss.qualcomm.com?part=4