Remove the unwanted reads of hc_irq_cause from mv_host_intr(),
thereby removing a bug whereby we were not always reading it when needed..
Signed-off-by: Mark Lord <mlord@xxxxxxxxx>
--- old/drivers/ata/sata_mv.c 2008-05-01 20:01:29.000000000 -0400
+++ linux/drivers/ata/sata_mv.c 2008-05-01 20:15:59.000000000 -0400
@@ -1818,48 +1818,61 @@
static int mv_host_intr(struct ata_host *host, u32 main_irq_cause)
{
struct mv_host_priv *hpriv = host->private_data;
- void __iomem *mmio = hpriv->base, *hc_mmio = NULL;
- u32 hc_irq_cause = 0;
+ void __iomem *mmio = hpriv->base, *hc_mmio;
unsigned int handled = 0, port;
for (port = 0; port < hpriv->n_ports; port++) {
struct ata_port *ap = host->ports[port];
struct mv_port_priv *pp;
- unsigned int shift, hardport, port_cause;
- /*
- * When we move to the second hc, flag our cached
- * copies of hc_mmio (and hc_irq_cause) as invalid again.
- */
- if (port == MV_PORTS_PER_HC)
- hc_mmio = NULL;
- /*
- * Do nothing if port is not interrupting or is disabled:
- */
+ unsigned int p, shift, hardport, port_cause;
+
MV_PORT_TO_SHIFT_AND_HARDPORT(port, shift, hardport);
- port_cause = (main_irq_cause >> shift) & (DONE_IRQ | ERR_IRQ);
- if (!port_cause || !ap || (ap->flags & ATA_FLAG_DISABLED))
- continue;
/*
- * Each hc within the host has its own hc_irq_cause register.
- * We defer reading it until we know we need it, right now:
- *
- * FIXME later: we don't really need to read this register
- * (some logic changes required below if we go that way),
- * because it doesn't tell us anything new. But we do need
- * to write to it, outside the top of this loop,
- * to reset the interrupt triggers for next time.
+ * Each hc within the host has its own hc_irq_cause register,
+ * where the interrupting ports bits get ack'd.
*/
- if (!hc_mmio) {
+ if (hardport == 0) { /* first port on this hc ? */
+ u32 hc_cause = (main_irq_cause >> shift) & HC0_IRQ_PEND;
+ u32 port_mask, ack_irqs;
+ /*
+ * Skip this entire hc if nothing pending for any ports
+ */
+ if (!hc_cause) {
+ port += MV_PORTS_PER_HC - 1;
+ continue;
+ }
+ /*
+ * We don't need/want to read the hc_irq_cause register,
+ * because doing so hurts performance, and
+ * main_irq_cause already gives us everything we need.
+ *
+ * But we do have to *write* to the hc_irq_cause to ack
+ * the ports that we are handling this time through.
+ *
+ * This requires that we create a bitmap for those
+ * ports which interrupted us, and use that bitmap
+ * to ack (only) those ports via hc_irq_cause.
+ */
+ ack_irqs = 0;
+ for (p = 0; p < MV_PORTS_PER_HC; ++p) {
+ if ((port + p) >= hpriv->n_ports)
+ break;
+ port_mask = (DONE_IRQ | ERR_IRQ) << (p * 2);
+ if (hc_cause & port_mask)
+ ack_irqs |= (DMA_IRQ | DEV_IRQ) << p;
+ }
hc_mmio = mv_hc_base_from_port(mmio, port);
- hc_irq_cause = readl(hc_mmio + HC_IRQ_CAUSE_OFS);
- writelfl(~hc_irq_cause, hc_mmio + HC_IRQ_CAUSE_OFS);
+ writelfl(~ack_irqs, hc_mmio + HC_IRQ_CAUSE_OFS);
handled = 1;
}
+ port_cause = (main_irq_cause >> shift) & (DONE_IRQ | ERR_IRQ);
+ if (!port_cause)
+ continue;
/*
* Process completed CRPB response(s) before other events.
*/
pp = ap->private_data;
- if (hc_irq_cause & (DMA_IRQ << hardport)) {
+ if (port_cause & DONE_IRQ) {
if (pp->pp_flags & MV_PP_FLAG_EDMA_EN)
mv_process_crpb_entries(ap, pp);
}
@@ -1868,15 +1881,15 @@
*/
if (unlikely(port_cause & ERR_IRQ)) {
mv_err_intr(ap);
- } else if (hc_irq_cause & (DEV_IRQ << hardport)) {
+ } else {
if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN)) {
struct ata_queued_cmd *qc = mv_get_active_qc(ap);
if (qc) {
ata_sff_host_intr(ap, qc);
continue;
}
+ mv_unexpected_intr(ap);
}
- mv_unexpected_intr(ap);
}
}
return handled;
--
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