Re: [PATCH V3 2/2] PCI: dwc: Add support to configure for ECRC

[Vidya Sagar <vidyas@nvidia.com>]

On 11/2/2020 7:45 PM, Rob Herring wrote:
> External email: Use caution opening links or attachments
> 
> 
> On Thu, Oct 29, 2020 at 12:40 AM Vidya Sagar <vidyas@nvidia.com> wrote:
>>
>> DesignWare core has a TLP digest (TD) override bit in one of the control
>> registers of ATU. This bit also needs to be programmed for proper ECRC
>> functionality. This is currently identified as an issue with DesignWare
>> IP version 4.90a. This patch does the required programming in ATU upon
>> querying the system policy for ECRC.
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> Reviewed-by: Jingoo Han <jingoohan1@gmail.com>
>> ---
>> V3:
>> * Added 'Reviewed-by: Jingoo Han <jingoohan1@gmail.com>'
>>
>> V2:
>> * Addressed Jingoo's review comment
>> * Removed saving 'td' bit information in 'dw_pcie' structure
>>
>>   drivers/pci/controller/dwc/pcie-designware.c | 8 ++++++--
>>   drivers/pci/controller/dwc/pcie-designware.h | 1 +
>>   2 files changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
>> index b5e438b70cd5..cbd651b219d2 100644
>> --- a/drivers/pci/controller/dwc/pcie-designware.c
>> +++ b/drivers/pci/controller/dwc/pcie-designware.c
>> @@ -246,6 +246,8 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
>>          dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
>>                                   upper_32_bits(pci_addr));
>>          val = type | PCIE_ATU_FUNC_NUM(func_no);
>> +       if (pci->version == 0x490A)
>> +               val = val | pcie_is_ecrc_enabled() << PCIE_ATU_TD_SHIFT;
>>          val = upper_32_bits(size - 1) ?
>>                  val | PCIE_ATU_INCREASE_REGION_SIZE : val;
>>          dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1, val);
>> @@ -294,8 +296,10 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
>>                             lower_32_bits(pci_addr));
>>          dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_TARGET,
>>                             upper_32_bits(pci_addr));
>> -       dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, type |
>> -                          PCIE_ATU_FUNC_NUM(func_no));
>> +       val = type | PCIE_ATU_FUNC_NUM(func_no);
>> +       if (pci->version == 0x490A)
> 
> Is this even possible? Are the non-unroll ATU registers available post 4.80?
I'm not sure. Gustavo might have information about this. I made this 
change so that it is taken care off even if they available.

> 
> Rob
>