RE: [PATCHv3 24/27] PCI: mobiveil: ls_pcie_g4: add Workaround for A-011577

["Z.q. Hou" <zhiqiang.hou@nxp.com>]

Hi Subbu,

Thanks a lot for your comments!

> -----Original Message-----
> From: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
> Sent: 2019年2月8日 20:52
> To: Z.q. Hou <zhiqiang.hou@nxp.com>
> Cc: linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
> bhelgaas@google.com; robh+dt@kernel.org; mark.rutland@arm.com;
> shawnguo@kernel.org; Leo Li <leoyang.li@nxp.com>;
> lorenzo.pieralisi@arm.com; catalin.marinas@arm.com;
> will.deacon@arm.com; Mingkai Hu <mingkai.hu@nxp.com>; M.h. Lian
> <minghuan.lian@nxp.com>; Xiaowei Bao <xiaowei.bao@nxp.com>
> Subject: Re: [PATCHv3 24/27] PCI: mobiveil: ls_pcie_g4: add Workaround for
> A-011577
> 
> ZQ,
> 
> On Tue, Jan 29, 2019 at 1:41 PM Z.q. Hou <zhiqiang.hou@nxp.com> wrote:
> >
> > From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> >
> > PCIe configuration access to non-existent function triggered SERROR
> > interrupt exception.
> >
> > Workaround:
> > Disable error reporting on AXI bus during the Vendor ID read
> > transactions in enumeration.
> >
> > This ERRATA is only for LX2160A Rev1.0, and it will be fixed in
> > Rev2.0.
> >
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> > ---
> > V3:
> >  - Integrated without change from
> >
> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpatc
> >
> hwork.ozlabs.org%2Fpatch%2F1006790%2F&amp;data=02%7C01%7Czhiqian
> g.hou%
> >
> 40nxp.com%7C122074f0ac6d4b46ca8208d68dc3e7ac%7C686ea1d3bc2b4c6f
> a92cd99
> >
> c5c301635%7C0%7C0%7C636852269885449903&amp;sdata=IfAadaAfHuGS
> %2FJCyH4X
> > TQEnPV1HM3huKjRVDK%2BAbv8M%3D&amp;reserved=0
> >
> >  .../controller/mobiveil/pci-layerscape-gen4.c | 37
> > +++++++++++++++++++  .../controller/mobiveil/pcie-mobiveil-host.c  |
> 17 ++++++++-
> >  .../pci/controller/mobiveil/pcie-mobiveil.h   |  3 ++
> >  3 files changed, 56 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
> > b/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
> > index 174cbcac4059..d2c5dbbd5e3c 100644
> > --- a/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
> > +++ b/drivers/pci/controller/mobiveil/pci-layerscape-gen4.c
> > @@ -22,8 +22,13 @@
> >
> >  #include "pcie-mobiveil.h"
> >
> > +#define REV_1_0                                (0x10)
> > +
> >  /* LUT and PF control registers */
> >  #define PCIE_LUT_OFF                   (0x80000)
> > +#define PCIE_LUT_GCR                   (0x28)
> > +#define PCIE_LUT_GCR_RRE               (0)
> > +
> >  #define PCIE_PF_OFF                    (0xc0000)
> >  #define PCIE_PF_INT_STAT               (0x18)
> >  #define PF_INT_STAT_PABRST             (31)
> > @@ -41,6 +46,7 @@ struct ls_pcie_g4 {
> >         struct mobiveil_pcie *pci;
> >         struct delayed_work dwork;
> >         int irq;
> > +       u8 rev;
> >  };
> >
> >  static inline u32 ls_pcie_g4_lut_readl(struct ls_pcie_g4 *pcie, u32
> > off) @@ -76,6 +82,15 @@ static bool ls_pcie_g4_is_bridge(struct
> ls_pcie_g4 *pcie)
> >         return header_type == PCI_HEADER_TYPE_BRIDGE;  }
> >
> > +static int ls_pcie_g4_host_init(struct mobiveil_pcie *pci) {
> > +       struct ls_pcie_g4 *pcie = to_ls_pcie_g4(pci);
> > +
> > +       pcie->rev = csr_readb(pci, PCI_REVISION_ID);
> > +
> > +       return 0;
> > +}
> > +
> >  static int ls_pcie_g4_link_up(struct mobiveil_pcie *pci)  {
> >         struct ls_pcie_g4 *pcie = to_ls_pcie_g4(pci); @@ -188,12
> > +203,34 @@ static void ls_pcie_g4_reset(struct work_struct *work)
> >         ls_pcie_g4_reinit_hw(pcie);
> >  }
> >
> > +static int ls_pcie_g4_read_other_conf(struct pci_bus *bus, unsigned int
> devfn,
> > +                                  int where, int size, u32 *val) {
> > +       struct mobiveil_pcie *pci = bus->sysdata;
> > +       struct ls_pcie_g4 *pcie = to_ls_pcie_g4(pci);
> > +       int ret;
> > +
> > +       if (pcie->rev == REV_1_0 && where == PCI_VENDOR_ID)
> > +               ls_pcie_g4_lut_writel(pcie, PCIE_LUT_GCR,
> > +                                     0 << PCIE_LUT_GCR_RRE);
> > +
> > +       ret = pci_generic_config_read(bus, devfn, where, size, val);
> > +
> > +       if (pcie->rev == REV_1_0 && where == PCI_VENDOR_ID)
> > +               ls_pcie_g4_lut_writel(pcie, PCIE_LUT_GCR,
> > +                                     1 << PCIE_LUT_GCR_RRE);
> > +
> > +       return ret;
> > +}
> > +
> >  static struct mobiveil_rp_ops ls_pcie_g4_rp_ops = {
> >         .interrupt_init = ls_pcie_g4_interrupt_init,
> > +       .read_other_conf = ls_pcie_g4_read_other_conf,
> >  };
> >
> >  static const struct mobiveil_pab_ops ls_pcie_g4_pab_ops = {
> >         .link_up = ls_pcie_g4_link_up,
> > +       .host_init = ls_pcie_g4_host_init,
> >  };
> >
> >  static int __init ls_pcie_g4_probe(struct platform_device *pdev) diff
> > --git a/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
> > b/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
> > index e8d0c4989013..5f51bc2dd6d7 100644
> > --- a/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
> > +++ b/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
> > @@ -79,9 +79,20 @@ static void __iomem *mobiveil_pcie_map_bus(struct
> pci_bus *bus,
> >         return pcie->rp.config_axi_slave_base + where;  }
> >
> > +static int mobiveil_pcie_config_read(struct pci_bus *bus, unsigned int
> devfn,
> > +                                    int where, int size, u32 *val) {
> > +       struct mobiveil_pcie *pcie = bus->sysdata;
> > +       struct root_port *rp = &pcie->rp;
> > +
> > +       if (bus->number > rp->root_bus_nr &&
> rp->ops->read_other_conf)
> > +               return rp->ops->read_other_conf(bus, devfn, where,
> > + size, val);
> > +
> > +       return pci_generic_config_read(bus, devfn, where, size, val);
> > +}
> >  static struct pci_ops mobiveil_pcie_ops = {
> >         .map_bus = mobiveil_pcie_map_bus,
> > -       .read = pci_generic_config_read,
> > +       .read = mobiveil_pcie_config_read,
> >         .write = pci_generic_config_write,  };
> >
> > @@ -309,6 +320,10 @@ int mobiveil_host_init(struct mobiveil_pcie *pcie,
> bool reinit)
> >         value |= (PCI_CLASS_BRIDGE_PCI << 16);
> >         csr_writel(pcie, value, PAB_INTP_AXI_PIO_CLASS);
> >
> > +       /* Platform specific host init */
> > +       if (pcie->ops->host_init)
> > +               return pcie->ops->host_init(pcie);
> > +
> >         return 0;
> >  }
> >
> > diff --git a/drivers/pci/controller/mobiveil/pcie-mobiveil.h
> > b/drivers/pci/controller/mobiveil/pcie-mobiveil.h
> > index 0ccd6cee5f8f..ab43de5e4b2b 100644
> > --- a/drivers/pci/controller/mobiveil/pcie-mobiveil.h
> > +++ b/drivers/pci/controller/mobiveil/pcie-mobiveil.h
> > @@ -145,6 +145,8 @@ struct mobiveil_msi
> {                       /* MSI information */
> >
> >  struct mobiveil_rp_ops {
> >         int (*interrupt_init)(struct mobiveil_pcie *pcie);
> > +       int (*read_other_conf)(struct pci_bus *bus, unsigned int devfn,
> > +                              int where, int size, u32 *val);
> >  };
> >
> >  struct root_port {
> > @@ -160,6 +162,7 @@ struct root_port {
> >
> >  struct mobiveil_pab_ops {
> >         int (*link_up)(struct mobiveil_pcie *pcie);
> > +       int (*host_init)(struct mobiveil_pcie *pcie);
> >  };
> >
> >  struct mobiveil_pcie {
> > --
> > 2.17.1
> >
> can we have an english brief than having a internal cryptic number:A-011577,
> on the patch title?

I think it is unnecessary to make a redundant title for the ERRATA patch and the commit message has the ERRATA description.

Thanks,
Zhiqiang