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

[Vidya Sagar]

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@xxxxxxxxxx> 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@xxxxxxxxxx>
> > Reviewed-by: Jingoo Han <jingoohan1@xxxxxxxxx>
> > ---
> > V3:
> > * Added 'Reviewed-by: Jingoo Han <jingoohan1@xxxxxxxxx>'
> >
> > 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