[PATCH v7 0/2] PCI: cadence: Retrain Link to work around Gen2

[Tom Joseph]

> -----Original Message-----
> From: Nadeem Athani <nadeem at cadence.com>
> Sent: 30 December 2020 12:05
> To: Tom Joseph <tjoseph at cadence.com>; lorenzo.pieralisi at arm.com;
> robh at kernel.org; bhelgaas at google.com; kishon at ti.com; linux-
> omap at vger.kernel.org; linux-pci at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org; linux-kernel at vger.kernel.org
> Cc: Athani Nadeem Ladkhan <nadeem at cadence.com>; Milind Parab
> <mparab at cadence.com>; Swapnil Kashinath Jakhade
> <sjakhade at cadence.com>; Parshuram Raju Thombare
> <pthombar at cadence.com>
> Subject: [PATCH v7 0/2] PCI: cadence: Retrain Link to work around Gen2
> 
> 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 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 | 70
> ++++++++++++++++------
>  drivers/pci/controller/cadence/pcie-cadence.h      | 11 +++-
>  3 files changed, 65 insertions(+), 19 deletions(-)

Reviewed-by: Tom Joseph <tjoseph at cadence.com>


Thanks,
Tom