Messages in this thread Patch in this message | | | Date | Tue, 23 Jan 2007 20:09:02 -0600 | From | Robert Hancock <> | Subject | [PATCH 2.6.20] sata_nv: don't rely on NV_INT_DEV indication with ADMA |
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OK, here it is in full signed-off glory. Hopefully we can get this in for 2.6.20.
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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>
--- linux-2.6.20-rc5/drivers/ata/sata_nv.c 2007-01-19 19:18:53.000000000 -0600 +++ linux-2.6.20-rc5debug/drivers/ata/sata_nv.c 2007-01-22 22:33:43.000000000 -0600 @@ -700,7 +700,6 @@ static void nv_adma_check_cpb(struct ata 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 } /* 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 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; } | |