[PATCH 2.6.20] sata_nv: don't rely on NV_INT_DEV indication with ADMA
OK, here it is in full signed-off glory. Hopefully we can get this in
for 2.6.20.
---
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 <[EMAIL PROTECTED]>
--- linux-2.6.20-rc5/drivers/ata/sata_nv.c 2007-01-19 19:18:53.0
-0600
+++ linux-2.6.20-rc5debug/drivers/ata/sata_nv.c 2007-01-22 22:33:43.0
-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;
}
[PATCH 2.6.20] sata_nv: don't rely on NV_INT_DEV indication with ADMA
OK, here it is in full signed-off glory. Hopefully we can get this in
for 2.6.20.
---
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 [EMAIL PROTECTED]
--- linux-2.6.20-rc5/drivers/ata/sata_nv.c 2007-01-19 19:18:53.0
-0600
+++ linux-2.6.20-rc5debug/drivers/ata/sata_nv.c 2007-01-22 22:33:43.0
-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;
}
