sata_nv: don't rely on NV_INT_DEV indication with ADMA (f740d168) · Commits · 戴 / test

Several people reported issues with certain drive commands timing out on sata_nv controllers running in ADMA mode. The commands in question were non-DMA-mapped commands, usually FLUSH CACHE or FLUSH CACHE EXT. From experimentation it appears that the NV_INT_DEV indication isn't always set when a legitimate command completion interrupt is received on a legacy-mode command, at least not on these controllers in ADMA mode. When a command is pending on the port, force the flag on always in the irq_stat value before calling nv_host_intr so that the drive busy state is always checked by ata_host_intr. This also fixes some questionable code in nv_host_intr which called ata_check_status when a command was pending and ata_host_intr returned "unhandled". If the device interrupted at just the wrong time this could cause interrupts to be lost. Signed-off-by:

Robert Hancock <hancockr@shaw.ca> Signed-off-by:

Jeff Garzik <jeff@garzik.org>

drivers/ata/sata_nv.c

+6 −8

Original line number	Diff line number	Diff line
		@@ -700,7 +700,6 @@ static void nv_adma_check_cpb(struct ata_port *ap, int cpb_num, int force_err)
		static int nv_host_intr(struct ata_port *ap, u8 irq_stat)
		{
		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->active_tag);
		int handled;

		/* freeze if hotplugged */
		if (unlikely(irq_stat & (NV_INT_ADDED \| NV_INT_REMOVED))) {
		@@ -719,13 +718,7 @@ static int nv_host_intr(struct ata_port *ap, u8 irq_stat)
		}

		/* handle interrupt */
		handled = ata_host_intr(ap, qc);
		if (unlikely(!handled)) {
		/* spurious, clear it */
		ata_check_status(ap);
		}

		return 1;
		return ata_host_intr(ap, qc);
		}

		static irqreturn_t nv_adma_interrupt(int irq, void *dev_instance)
		@@ -752,6 +745,11 @@ static irqreturn_t nv_adma_interrupt(int irq, void *dev_instance)
		if (pp->flags & NV_ADMA_PORT_REGISTER_MODE) {
		u8 irq_stat = readb(host->mmio_base + NV_INT_STATUS_CK804)
		>> (NV_INT_PORT_SHIFT * i);
		if(ata_tag_valid(ap->active_tag))
		/** NV_INT_DEV indication seems unreliable at times
		at least in ADMA mode. Force it on always when a
		command is active, to prevent losing interrupts. */
		irq_stat \|= NV_INT_DEV;
		handled += nv_host_intr(ap, irq_stat);
		continue;
		}

Admin message