On Apr 2, 2013, at 9:03 PM, Jia Hongtao wrote:
> The MPIC version 2.0 has a MSI errata (errata PIC1 of mpc8544), It causes
> that neither MSI nor MSI-X can work fine. This is a workaround to allow
> MSI-X to function properly.
>
> Signed-off-by: Liu Shuo <soniccat....@gmail.com>
> Signed-off-by: Li Yang <le...@freescale.com>
> Signed-off-by: Jia Hongtao <hongtao....@freescale.com>
> ---
> Changes for V2:
> * change the name of function mpic_has_errata() to mpic_has_erratum_pic1().
> * move MSI_HW_ERRATA_ENDIAN define to fsl_msi.h with all other defines.
>
> arch/powerpc/sysdev/fsl_msi.c | 40 +++++++++++++++++++++++++++++++++++++---
> arch/powerpc/sysdev/fsl_msi.h | 2 ++
> 2 files changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
> index 178c994..ca1157a 100644
> --- a/arch/powerpc/sysdev/fsl_msi.c
> +++ b/arch/powerpc/sysdev/fsl_msi.c
> @@ -98,8 +98,18 @@ static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
>
> static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
> {
> - if (type == PCI_CAP_ID_MSIX)
> - pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
> + struct fsl_msi *msi;
> +
> + if (type == PCI_CAP_ID_MSI) {
> + /*
> + * MPIC version 2.0 has erratum PIC1. For now MSI
> + * could not work. So check to prevent MSI from
> + * being used on the board with this erratum.
> + */
> + list_for_each_entry(msi, &msi_head, list)
> + if (msi->feature & MSI_HW_ERRATA_ENDIAN)
> + return -EINVAL;
> + }
>
> return 0;
> }
> @@ -142,7 +152,17 @@ static void fsl_compose_msi_msg(struct pci_dev *pdev,
> int hwirq,
> msg->address_lo = lower_32_bits(address);
> msg->address_hi = upper_32_bits(address);
>
> - msg->data = hwirq;
> + /*
> + * MPIC version 2.0 has erratum PIC1. It causes
> + * that neither MSI nor MSI-X can work fine.
> + * This is a workaround to allow MSI-X to function
> + * properly. It only works for MSI-X, we prevent
> + * MSI on buggy chips in fsl_msi_check_device().
> + */
> + if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
> + msg->data = __swab32(hwirq);
> + else
> + msg->data = hwirq;
>
> pr_debug("%s: allocated srs: %d, ibs: %d\n",
> __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
> @@ -361,6 +381,15 @@ static int fsl_msi_setup_hwirq(struct fsl_msi *msi,
> struct platform_device *dev,
> return 0;
> }
>
> +/* MPIC version 2.0 has erratum PIC1 */
> +static int mpic_has_erratum_pic1(void)
> +{
> + if (fsl_mpic_primary_get_version() == 0x0200)
> + return 1;
> +
> + return 0;
> +}
> +
> static const struct of_device_id fsl_of_msi_ids[];
> static int fsl_of_msi_probe(struct platform_device *dev)
> {
> @@ -423,6 +452,11 @@ static int fsl_of_msi_probe(struct platform_device *dev)
>
> msi->feature = features->fsl_pic_ip;
>
> + if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) == FSL_PIC_IP_MPIC) {
> + if (mpic_has_erratum_pic1())
Get ride of the mpic_has_erratum_pic1() function and just put the test here
> + msi->feature |= MSI_HW_ERRATA_ENDIAN;
> + }
> +
> /*
> * Remember the phandle, so that we can match with any PCI nodes
> * that have an "fsl,msi" property.
> diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
> index 8225f86..7389e8e 100644
> --- a/arch/powerpc/sysdev/fsl_msi.h
> +++ b/arch/powerpc/sysdev/fsl_msi.h
> @@ -25,6 +25,8 @@
> #define FSL_PIC_IP_IPIC 0x00000002
> #define FSL_PIC_IP_VMPIC 0x00000003
>
> +#define MSI_HW_ERRATA_ENDIAN 0x00000010
> +
Why does this need to be in the header, why not just have it in the .c only
> struct fsl_msi {
> struct irq_domain *irqhost;
>
> --
> 1.8.0
>
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