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authorHongtao Jia <hongtao.jia@freescale.com>2015-02-26 10:23:08 +0300
committerScott Wood <scottwood@freescale.com>2015-03-24 03:51:18 +0300
commitff015659b631621fc9d60403a5dfbdf72c1cd058 (patch)
tree493c005e167a3a531c8e3363a423139c93ba58be /arch/powerpc/sysdev
parent807d38b73b63bbbaa8e1baacf76f7874992f91e8 (diff)
downloadlinux-ff015659b631621fc9d60403a5dfbdf72c1cd058.tar.xz
powerpc/85xx: workaround for chips with MSI hardware errata
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.liu@gmail.com> Signed-off-by: Li Yang <leoli@freescale.com> Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc/sysdev')
-rw-r--r--arch/powerpc/sysdev/fsl_msi.c29
-rw-r--r--arch/powerpc/sysdev/fsl_msi.h2
2 files changed, 28 insertions, 3 deletions
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 4bbb4b8dfd09..f086c6f22dc9 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -162,7 +162,17 @@ 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_setup_msi_irqs().
+ */
+ 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 >> msi_data->srs_shift) & MSI_SRS_MASK,
@@ -180,8 +190,16 @@ static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
struct msi_msg msg;
struct fsl_msi *msi_data;
- if (type == PCI_CAP_ID_MSIX)
- pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
+ 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_data, &msi_head, list)
+ if (msi_data->feature & MSI_HW_ERRATA_ENDIAN)
+ return -EINVAL;
+ }
/*
* If the PCI node has an fsl,msi property, then we need to use it
@@ -446,6 +464,11 @@ static int fsl_of_msi_probe(struct platform_device *dev)
msi->feature = features->fsl_pic_ip;
+ /* For erratum PIC1 on MPIC version 2.0*/
+ if ((features->fsl_pic_ip & FSL_PIC_IP_MASK) == FSL_PIC_IP_MPIC
+ && (fsl_mpic_primary_get_version() == 0x0200))
+ 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 420cfcbdac01..a67359d993e5 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -27,6 +27,8 @@
#define FSL_PIC_IP_IPIC 0x00000002
#define FSL_PIC_IP_VMPIC 0x00000003
+#define MSI_HW_ERRATA_ENDIAN 0x00000010
+
struct fsl_msi_cascade_data;
struct fsl_msi {