[v8,0/2] PCI: cadence: Retrain Link to work around Gen2

Message

Athani Nadeem Ladkhan Feb. 9, 2021, 2:46 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 v8:
- Adding a new function cdns_pcie_host_start_link().
Changes in v7:
- Changing the commit title of patch 1 in this series.
- Added a return value for function cdns_pcie_retrain().
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: Shifting of a function to support new code.
  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 | 81 +++++++++++++++++-----
 drivers/pci/controller/cadence/pcie-cadence.h      | 11 ++-
 3 files changed, 76 insertions(+), 19 deletions(-)

Comments

Lorenzo Pieralisi Feb. 10, 2021, 12:52 p.m. UTC | #1

On Tue, 9 Feb 2021 15:46:20 +0100, Nadeem Athani wrote:
> 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 v8:
> - Adding a new function cdns_pcie_host_start_link().
> Changes in v7:
> - Changing the commit title of patch 1 in this series.
> - Added a return value for function cdns_pcie_retrain().
> 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.
> 
> [...]

Applied to pci/cadence, squashed two commits together since it makes
no sense to keep them separate. Also, please check:

git log --oneline

when writing patches to keep the changes uniform, I had to edit your
commit.

Thanks,
Lorenzo