Commit 96e2c487 authored by Mark Lord's avatar Mark Lord Committed by Jeff Garzik
Browse files

sata_mv: cache main_irq_mask register in hpriv 



Part five of simplifying/fixing handling of the main_irq_mask register
to resolve unexpected interrupt issues observed in 2.6.26-rc*.

Keep a cached copy of the main_irq_mask so that we don't have
to stall the CPU to read it on every pass through mv_interrupt.

This significantly speeds up interrupt handling, both for sata_mv,
and for any other driver/device sharing the same PCI IRQ line.

Signed-off-by: default avatarMark Lord <mlord@pobox.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent a44253d2

drivers/ata/sata_mv.c

+7 −5
Original line number Diff line number Diff line
@@ -458,6 +458,7 @@ struct mv_port_signal { 


struct mv_host_priv {

	u32			hp_flags;

	u32			main_irq_mask;

	struct mv_port_signal	signal[8];

	const struct mv_hw_ops	*ops;

	int			n_ports;
@@ -843,11 +844,13 @@ static void mv_set_main_irq_mask(struct ata_host *host, 
	struct mv_host_priv *hpriv = host->private_data;

	u32 old_mask, new_mask;



	old_mask = readl(hpriv->main_irq_mask_addr);

	old_mask = hpriv->main_irq_mask;

	new_mask = (old_mask & ~disable_bits) | enable_bits;

	if (new_mask != old_mask)

	if (new_mask != old_mask) {

		hpriv->main_irq_mask = new_mask;

		writelfl(new_mask, hpriv->main_irq_mask_addr);

	}

}



static void mv_enable_port_irqs(struct ata_port *ap,

				     unsigned int port_bits)
@@ -2200,12 +2203,11 @@ static irqreturn_t mv_interrupt(int irq, void *dev_instance) 
	struct ata_host *host = dev_instance;

	struct mv_host_priv *hpriv = host->private_data;

	unsigned int handled = 0;

	u32 main_irq_cause, main_irq_mask, pending_irqs;

	u32 main_irq_cause, pending_irqs;



	spin_lock(&host->lock);

	main_irq_cause = readl(hpriv->main_irq_cause_addr);

	main_irq_mask  = readl(hpriv->main_irq_mask_addr);

	pending_irqs   = main_irq_cause & main_irq_mask;

	pending_irqs   = main_irq_cause & hpriv->main_irq_mask;

	/*

	 * Deal with cases where we either have nothing pending, or have read

	 * a bogus register value which can indicate HW removal or PCI fault.

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