[PATCH v4 0/3] PCI: dwc: Skip waiting for link up if vendor drivers can detect Link up event

[Krishna chaitanya chundru <quic_krichai@quicinc.com>]

If the vendor drivers can detect the Link up event using mechanisms
such as Link up IRQ, then waiting for Link up during probe is not
needed. if the drivers can be notified when the link comes up,
vendor driver can enumerate downstream devices instead of waiting
here, which optimizes the boot time.

So skip waiting for link to be up if the driver supports 'linkup_irq'.

Currently, only Qcom RC driver supports the 'linkup_irq' as it can detect
the Link Up event using its own 'global IRQ' interrupt. So set
'linkup_irq' flag for QCOM drivers.

As part of the PCIe link up event, the ICC and OPP values are updated.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
Changes in v4:
- change the linkup_irq name to use_linkup_irq a suggested by (bjorn
  andresson)
- update commit text as suggested by bjorn andresson.
- Link to v3: https://lore.kernel.org/r/linux-arm-msm/20241101-remove_wait-v3-0-7accf27f7202@quicinc.com/T/
Changes in v3:
- seperate dwc changes and qcom changes as suggested (mani)
- update commit & comments as suggested (mani & bjorn)
- Link to v2: https://lore.kernel.org/linux-pci/20240920-remove_wait-v2-0-7c0fcb3b581d@quicinc.com/T/
Changes in v2:
- Updated the bypass_link_up_wait name to linkup_irq  & added comment as
  suggested (mani).
- seperated the icc and opp update patch (mani).
- Link to v1: https://lore.kernel.org/r/20240917-remove_wait-v1-1-456d2551bc50@quicinc.com

---
Krishna chaitanya chundru (3):
      PCI: dwc: Skip waiting for link up if vendor drivers can detect Link up event
      PCI: qcom: Set linkup_irq if global IRQ handler is present
      PCI: qcom: Update ICC and OPP values during link up event

 drivers/pci/controller/dwc/pcie-designware-host.c | 10 ++++++++--
 drivers/pci/controller/dwc/pcie-designware.h      |  1 +
 drivers/pci/controller/dwc/pcie-qcom.c            |  7 ++++++-
 3 files changed, 15 insertions(+), 3 deletions(-)
---
base-commit: 624ce1863d33298cd1623e51006147e4076ed2ca
change-id: 20241114-remove_wait1-289beeba1989

Best regards,
-- 
Krishna chaitanya chundru <quic_krichai@quicinc.com>