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path: root/arch/powerpc/platforms/cell/axon_msi.c
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Diffstat (limited to 'arch/powerpc/platforms/cell/axon_msi.c')
-rw-r--r--arch/powerpc/platforms/cell/axon_msi.c36
1 files changed, 31 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index 896548ba1ca..442cf36aa17 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -95,6 +95,7 @@ static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
struct axon_msic *msic = get_irq_data(irq);
u32 write_offset, msi;
int idx;
+ int retry = 0;
write_offset = dcr_read(msic->dcr_host, MSIC_WRITE_OFFSET_REG);
pr_debug("axon_msi: original write_offset 0x%x\n", write_offset);
@@ -102,7 +103,7 @@ static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
/* write_offset doesn't wrap properly, so we have to mask it */
write_offset &= MSIC_FIFO_SIZE_MASK;
- while (msic->read_offset != write_offset) {
+ while (msic->read_offset != write_offset && retry < 100) {
idx = msic->read_offset / sizeof(__le32);
msi = le32_to_cpu(msic->fifo_virt[idx]);
msi &= 0xFFFF;
@@ -110,13 +111,37 @@ static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
pr_debug("axon_msi: woff %x roff %x msi %x\n",
write_offset, msic->read_offset, msi);
+ if (msi < NR_IRQS && irq_map[msi].host == msic->irq_host) {
+ generic_handle_irq(msi);
+ msic->fifo_virt[idx] = cpu_to_le32(0xffffffff);
+ } else {
+ /*
+ * Reading the MSIC_WRITE_OFFSET_REG does not
+ * reliably flush the outstanding DMA to the
+ * FIFO buffer. Here we were reading stale
+ * data, so we need to retry.
+ */
+ udelay(1);
+ retry++;
+ pr_debug("axon_msi: invalid irq 0x%x!\n", msi);
+ continue;
+ }
+
+ if (retry) {
+ pr_debug("axon_msi: late irq 0x%x, retry %d\n",
+ msi, retry);
+ retry = 0;
+ }
+
msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
msic->read_offset &= MSIC_FIFO_SIZE_MASK;
+ }
- if (msi < NR_IRQS && irq_map[msi].host == msic->irq_host)
- generic_handle_irq(msi);
- else
- pr_debug("axon_msi: invalid irq 0x%x!\n", msi);
+ if (retry) {
+ printk(KERN_WARNING "axon_msi: irq timed out\n");
+
+ msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
+ msic->read_offset &= MSIC_FIFO_SIZE_MASK;
}
desc->chip->eoi(irq);
@@ -364,6 +389,7 @@ static int axon_msi_probe(struct of_device *device,
dn->full_name);
goto out_free_fifo;
}
+ memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
msic->irq_host = irq_alloc_host(dn, IRQ_HOST_MAP_NOMAP,
NR_IRQS, &msic_host_ops, 0);