sata_mv: optimize IRQ coalescing for 8-port chips
Enable use of the "all ports" IRQ coalescing optimization
for GEN_II / GEN_IIE chips that have dual host-controllers (8-ports).
Currently only the 6081 chip qualifies, but other chips may come along someday.
Rather than each half of the chip having to satisfy a local set of coalescing thresholds,
use of this feature groups all ports together under a single set of thresholds.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index ef38545..4718456 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -1016,7 +1016,7 @@
void __iomem *mmio = hpriv->base, *hc_mmio;
u32 coal_enable = 0;
unsigned long flags;
- unsigned int clks;
+ unsigned int clks, is_dual_hc = hpriv->n_ports > MV_PORTS_PER_HC;
const u32 coal_disable = PORTS_0_3_COAL_DONE | PORTS_4_7_COAL_DONE |
ALL_PORTS_COAL_DONE;
@@ -1033,37 +1033,41 @@
}
spin_lock_irqsave(&host->lock, flags);
+ mv_set_main_irq_mask(host, coal_disable, 0);
-#if 0 /* disabled pending functional clarification from Marvell */
- if (!IS_GEN_I(hpriv)) {
+ if (is_dual_hc && !IS_GEN_I(hpriv)) {
/*
- * GEN_II/GEN_IIE: global thresholds for the entire chip.
+ * GEN_II/GEN_IIE with dual host controllers:
+ * one set of global thresholds for the entire chip.
*/
writel(clks, mmio + MV_IRQ_COAL_TIME_THRESHOLD);
writel(count, mmio + MV_IRQ_COAL_IO_THRESHOLD);
/* clear leftover coal IRQ bit */
- writelfl(~ALL_PORTS_COAL_IRQ, mmio + MV_IRQ_COAL_CAUSE);
- clks = count = 0; /* so as to clear the alternate regs below */
- coal_enable = ALL_PORTS_COAL_DONE;
+ writel(~ALL_PORTS_COAL_IRQ, mmio + MV_IRQ_COAL_CAUSE);
+ if (count)
+ coal_enable = ALL_PORTS_COAL_DONE;
+ clks = count = 0; /* force clearing of regular regs below */
}
-#endif
+
/*
* All chips: independent thresholds for each HC on the chip.
*/
hc_mmio = mv_hc_base_from_port(mmio, 0);
writel(clks, hc_mmio + HC_IRQ_COAL_TIME_THRESHOLD_OFS);
writel(count, hc_mmio + HC_IRQ_COAL_IO_THRESHOLD_OFS);
- coal_enable |= PORTS_0_3_COAL_DONE;
- if (hpriv->n_ports > 4) {
+ writel(~HC_COAL_IRQ, hc_mmio + HC_IRQ_CAUSE_OFS);
+ if (count)
+ coal_enable |= PORTS_0_3_COAL_DONE;
+ if (is_dual_hc) {
hc_mmio = mv_hc_base_from_port(mmio, MV_PORTS_PER_HC);
writel(clks, hc_mmio + HC_IRQ_COAL_TIME_THRESHOLD_OFS);
writel(count, hc_mmio + HC_IRQ_COAL_IO_THRESHOLD_OFS);
- coal_enable |= PORTS_4_7_COAL_DONE;
+ writel(~HC_COAL_IRQ, hc_mmio + HC_IRQ_CAUSE_OFS);
+ if (count)
+ coal_enable |= PORTS_4_7_COAL_DONE;
}
- if (!count)
- coal_enable = 0;
- mv_set_main_irq_mask(host, coal_disable, coal_enable);
+ mv_set_main_irq_mask(host, 0, coal_enable);
spin_unlock_irqrestore(&host->lock, flags);
}