[v6,0/2] PCI: cadence: Retrain Link to work around Gen2

Message

Athani Nadeem Ladkhan Dec. 28, 2020, 2:05 p.m. UTC

Cadence controller will not initiate autonomous speed change if strapped 
as Gen2. The Retrain Link bit is set as quirk to enable this speed change.
Adding a quirk flag for defective IP. In future IP revisions this will not
be applicable.

Version history:
Changes in v6:
- Move the position of function cdns_pcie_host_wait_for_link to remove
  compilation error. No changes in code. Separate patch for this.
Changes in v5:
- Remove the compatible string based setting of quirk flag.
- Removed additional Link Up Check
- Removed quirk from pcie-cadence-plat.c and added in pci-j721e.c
Changes in v4:
- Added a quirk flag based on a new compatible string.
- Change of api for link up: cdns_pcie_host_wait_for_link().
Changes in v3:
- To set retrain link bit,checking device capability & link status.
- 32bit read in place of 8bit.
- Minor correction in patch comment.
- Change in variable & macro name.
Changes in v2:
- 16bit read in place of 8bit.

Nadeem Athani (2):
  PCI: cadence: Retrain Link to work around Gen2 training defect.
  PCI: cadence: Retrain Link to work around Gen2 training defect.

 drivers/pci/controller/cadence/pci-j721e.c         |  3 +
 drivers/pci/controller/cadence/pcie-cadence-host.c | 65 ++++++++++++++++------
 drivers/pci/controller/cadence/pcie-cadence.h      | 11 +++-
 3 files changed, 61 insertions(+), 18 deletions(-)