sata_sil24: fix IRQ clearing race when PCIX_IRQ_WOC is used (228f47b9) · Commits · 戴 / test

drivers/ata/sata_sil24.c

+12 −4

Original line number	Diff line number	Diff line
		@@ -888,6 +888,16 @@ static inline void sil24_host_intr(struct ata_port *ap)
		u32 slot_stat, qc_active;
		int rc;

		/* If PCIX_IRQ_WOC, there's an inherent race window between
		* clearing IRQ pending status and reading PORT_SLOT_STAT
		* which may cause spurious interrupts afterwards. This is
		* unavoidable and much better than losing interrupts which
		* happens if IRQ pending is cleared after reading
		* PORT_SLOT_STAT.
		*/
		if (ap->flags & SIL24_FLAG_PCIX_IRQ_WOC)
		writel(PORT_IRQ_COMPLETE, port + PORT_IRQ_STAT);

		slot_stat = readl(port + PORT_SLOT_STAT);

		if (unlikely(slot_stat & HOST_SSTAT_ATTN)) {
		@@ -895,9 +905,6 @@ static inline void sil24_host_intr(struct ata_port *ap)
		return;
		}

		if (ap->flags & SIL24_FLAG_PCIX_IRQ_WOC)
		writel(PORT_IRQ_COMPLETE, port + PORT_IRQ_STAT);

		qc_active = slot_stat & ~HOST_SSTAT_ATTN;
		rc = ata_qc_complete_multiple(ap, qc_active, sil24_finish_qc);
		if (rc > 0)
		@@ -910,7 +917,8 @@ static inline void sil24_host_intr(struct ata_port *ap)
		return;
		}

		if (ata_ratelimit())
		/* spurious interrupts are expected if PCIX_IRQ_WOC */
		if (!(ap->flags & SIL24_FLAG_PCIX_IRQ_WOC) && ata_ratelimit())
		ata_port_printk(ap, KERN_INFO, "spurious interrupt "
		"(slot_stat 0x%x active_tag %d sactive 0x%x)\n",
		slot_stat, ap->active_tag, ap->sactive);