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>
---
arch/powerpc/sysdev/fsl_msi.c | 47 ++++++++++++++++++++++++++++++++++++++++---
1 file changed, 44 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index 178c994..d2f8040 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -28,6 +28,8 @@
#include "fsl_msi.h"
#include "fsl_pci.h"
+#define MSI_HW_ERRATA_ENDIAN 0x00000010
+
static LIST_HEAD(msi_head);
struct fsl_msi_feature {
@@ -98,8 +100,18 @@ 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 +154,17 @@ 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 +383,15 @@ 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_errata(void)
+{
+ if (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 +454,16 @@ 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) {
+ rc = mpic_has_errata();
+ if (rc > 0) {
+ msi->feature |= MSI_HW_ERRATA_ENDIAN;
+ } else if (rc < 0) {
+ err = rc;
+ goto error_out;
+ }
+ }
+
/*
* Remember the phandle, so that we can match with any PCI nodes
* that have an "fsl,msi" property.
--
1.8.0
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