[PATCH v2 0/4] usb: xhci: prepare MSI path for secondary interrupters

[Xu Rao <raoxu@uniontech.com>]

Hi,

This series prepares the xHCI MSI path for secondary interrupters.

Instead of using struct usb_hcd as the MSI IRQ dev_id and deriving
interrupter 0 in the handler, pass struct xhci_interrupter as the IRQ
dev_id. This makes the MSI entry path operate on the same object that
owns the event ring and interrupter registers.

The primary path remains unchanged. Interrupter 0 is still the only
interrupter used by the normal xHCI path, and this series does not
enable extra vectors, change IRQ affinity, or add any new routing
policy.

USBSTS.EINT handling is also kept on interrupter 0. The bit is
controller-scoped, while IMAN.IP is per interrupter, so secondary
interrupters should not clear the controller-wide EINT status.

This is only a preparation step for future secondary interrupter users
and does not change the current primary xHCI interrupt behaviour.

Changes in v2:
- Patch 3 disables the primary interrupter before freeing the MSI IRQ,
  so the interrupt source is quiesced before releasing the vector.
- Patch 3 exports xhci_disable_interrupter() for xhci-pci module builds.

Xu Rao (4):
  usb: xhci: store xhci_hcd pointer in xhci_interrupter
  usb: xhci: route MSI through interrupter context
  usb: xhci-pci: use the interrupter entry as MSI dev_id
  usb: xhci: clear USBSTS EINT only for interrupter 0

 drivers/usb/host/xhci-mem.c  |  1 +
 drivers/usb/host/xhci-pci.c  |  9 +++++----
 drivers/usb/host/xhci.c      |  1 +
 drivers/usb/host/xhci-ring.c | 26 ++++++++++++++++++--------
 drivers/usb/host/xhci.h      |  1 +
 5 files changed, 26 insertions(+), 12 deletions(-)

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2.50.1