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From:   Rob Herring <robh@kernel.org>
Date:   Mon, 2 Nov 2020 08:15:47 -0600
Message-ID: <CAL_Jsq+3Ek9SRbsTqEmjiZtszvi7Er=TNgOt8t=0OESva2=sTg@mail.gmail.com>
Subject: Re: [PATCH V3 2/2] PCI: dwc: Add support to configure for ECRC
To:     Vidya Sagar <vidyas@nvidia.com>
Cc:     Jingoo Han <jingoohan1@gmail.com>,
        Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Andrew Murray <amurray@thegoodpenguin.co.uk>,
        Thierry Reding <treding@nvidia.com>,
        Jon Hunter <jonathanh@nvidia.com>,
        PCI <linux-pci@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        kthota@nvidia.com, Manikanta Maddireddy <mmaddireddy@nvidia.com>,
        sagar.tv@gmail.com
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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?

Rob