* [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci.
2016-01-27 9:49 [PATCH v2 0/3] ata: Fixes related to edge trigger latch for ahci_xgene driver Suman Tripathi
@ 2016-01-27 9:49 ` Suman Tripathi
2016-01-31 11:32 ` Tejun Heo
2016-01-27 9:49 ` [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler Suman Tripathi
2016-01-27 9:49 ` [PATCH v2 3/3] ahci_xgene: Implement the workaround to fix the missing of edge interrupt for HOST_IRQ_STAT Suman Tripathi
2 siblings, 1 reply; 8+ messages in thread
From: Suman Tripathi @ 2016-01-27 9:49 UTC (permalink / raw)
To: linux-arm-kernel
This patch removes the AHCI_HFLAG_EDGE_IRQ support from libahci.
The upcoming patches will have the flexibility to override
irq handlers in the LLD's. Controller's implementing a EDGE trigger
latch can implement their own interrupt handler inside the driver.
Signed-off-by: Suman Tripathi <stripathi@apm•com>
---
drivers/ata/ahci.h | 3 +--
drivers/ata/ahci_xgene.c | 2 +-
drivers/ata/libahci.c | 40 ----------------------------------------
3 files changed, 2 insertions(+), 43 deletions(-)
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index a4faa43..e9b57e8 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -240,8 +240,7 @@ enum {
error-handling stage) */
AHCI_HFLAG_NO_DEVSLP = (1 << 17), /* no device sleep */
AHCI_HFLAG_NO_FBS = (1 << 18), /* no FBS */
- AHCI_HFLAG_EDGE_IRQ = (1 << 19), /* HOST_IRQ_STAT behaves as
- Edge Triggered */
+
#ifdef CONFIG_PCI_MSI
AHCI_HFLAG_MULTI_MSI = (1 << 20), /* multiple PCI MSIs */
AHCI_HFLAG_MULTI_MSIX = (1 << 21), /* per-port MSI-X */
diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c
index e2c6d9e..892ec74 100644
--- a/drivers/ata/ahci_xgene.c
+++ b/drivers/ata/ahci_xgene.c
@@ -779,7 +779,7 @@ skip_clk_phy:
hpriv->flags = AHCI_HFLAG_NO_NCQ;
break;
case XGENE_AHCI_V2:
- hpriv->flags |= AHCI_HFLAG_YES_FBS | AHCI_HFLAG_EDGE_IRQ;
+ hpriv->flags |= AHCI_HFLAG_YES_FBS;
break;
default:
break;
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index eda3cf2..08be136 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1843,43 +1843,6 @@ static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
return handled;
}
-static irqreturn_t ahci_single_edge_irq_intr(int irq, void *dev_instance)
-{
- struct ata_host *host = dev_instance;
- struct ahci_host_priv *hpriv;
- unsigned int rc = 0;
- void __iomem *mmio;
- u32 irq_stat, irq_masked;
-
- VPRINTK("ENTER\n");
-
- hpriv = host->private_data;
- mmio = hpriv->mmio;
-
- /* sigh. 0xffffffff is a valid return from h/w */
- irq_stat = readl(mmio + HOST_IRQ_STAT);
- if (!irq_stat)
- return IRQ_NONE;
-
- irq_masked = irq_stat & hpriv->port_map;
-
- spin_lock(&host->lock);
-
- /*
- * HOST_IRQ_STAT behaves as edge triggered latch meaning that
- * it should be cleared before all the port events are cleared.
- */
- writel(irq_stat, mmio + HOST_IRQ_STAT);
-
- rc = ahci_handle_port_intr(host, irq_masked);
-
- spin_unlock(&host->lock);
-
- VPRINTK("EXIT\n");
-
- return IRQ_RETVAL(rc);
-}
-
static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance)
{
struct ata_host *host = dev_instance;
@@ -2507,9 +2470,6 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
rc = ahci_host_activate_multi_irqs(host, sht);
- else if (hpriv->flags & AHCI_HFLAG_EDGE_IRQ)
- rc = ata_host_activate(host, irq, ahci_single_edge_irq_intr,
- IRQF_SHARED, sht);
else
rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
IRQF_SHARED, sht);
--
1.7.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci.
2016-01-27 9:49 ` [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci Suman Tripathi
@ 2016-01-31 11:32 ` Tejun Heo
2016-02-01 19:45 ` Suman Tripathi
0 siblings, 1 reply; 8+ messages in thread
From: Tejun Heo @ 2016-01-31 11:32 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jan 27, 2016 at 03:19:55PM +0530, Suman Tripathi wrote:
> This patch removes the AHCI_HFLAG_EDGE_IRQ support from libahci.
> The upcoming patches will have the flexibility to override
> irq handlers in the LLD's. Controller's implementing a EDGE trigger
> latch can implement their own interrupt handler inside the driver.
>
> Signed-off-by: Suman Tripathi <stripathi@apm•com>
Shouldn't this patch come after the irq override is in place?
1. introduce irq override.
2. remove AHCI_HFLAG_EDGE_IRQ by moving the edge triggered handler to
ahci_xgene.
3. Update xgene irq handler to address the erratum.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci.
2016-01-31 11:32 ` Tejun Heo
@ 2016-02-01 19:45 ` Suman Tripathi
0 siblings, 0 replies; 8+ messages in thread
From: Suman Tripathi @ 2016-02-01 19:45 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jan 31, 2016 at 3:32 AM, Tejun Heo <htejun@gmail•com> wrote:
> On Wed, Jan 27, 2016 at 03:19:55PM +0530, Suman Tripathi wrote:
>> This patch removes the AHCI_HFLAG_EDGE_IRQ support from libahci.
>> The upcoming patches will have the flexibility to override
>> irq handlers in the LLD's. Controller's implementing a EDGE trigger
>> latch can implement their own interrupt handler inside the driver.
>>
>> Signed-off-by: Suman Tripathi <stripathi@apm•com>
>
> Shouldn't this patch come after the irq override is in place?
>
> 1. introduce irq override.
>
> 2. remove AHCI_HFLAG_EDGE_IRQ by moving the edge triggered handler to
> ahci_xgene.
>
> 3. Update xgene irq handler to address the erratum.
Thought of remove the AHCI_HFLAG_EDGE entirely first because we don't
require it . Then implement the irq override capability.
>
> Thanks.
>
> --
> tejun
--
Thanks,
with regards,
Suman Tripathi
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler.
2016-01-27 9:49 [PATCH v2 0/3] ata: Fixes related to edge trigger latch for ahci_xgene driver Suman Tripathi
2016-01-27 9:49 ` [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci Suman Tripathi
@ 2016-01-27 9:49 ` Suman Tripathi
2016-01-31 11:35 ` Tejun Heo
2016-01-27 9:49 ` [PATCH v2 3/3] ahci_xgene: Implement the workaround to fix the missing of edge interrupt for HOST_IRQ_STAT Suman Tripathi
2 siblings, 1 reply; 8+ messages in thread
From: Suman Tripathi @ 2016-01-27 9:49 UTC (permalink / raw)
To: linux-arm-kernel
This patch implements the capability to override the generic
ahci interrupt handler so that LDD drivers can implement there
own interrupt handler routines.
Signed-off-by: Suman Tripathi <stripathi@apm•com>
---
drivers/ata/ahci.h | 2 ++
drivers/ata/libahci.c | 13 ++++++++++---
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index e9b57e8..284ce3a 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -359,6 +359,7 @@ struct ahci_host_priv {
* be overridden anytime before the host is activated.
*/
void (*start_engine)(struct ata_port *ap);
+ irqreturn_t (*ahci_irq_intr)(int irq, void *dev_instance);
};
#ifdef CONFIG_PCI_MSI
@@ -422,6 +423,7 @@ int ahci_reset_em(struct ata_host *host);
void ahci_print_info(struct ata_host *host, const char *scc_s);
int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht);
void ahci_error_handler(struct ata_port *ap);
+u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked);
static inline void __iomem *__ahci_port_base(struct ata_host *host,
unsigned int port_no)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 08be136..fa098c6 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1816,7 +1816,7 @@ static irqreturn_t ahci_multi_irqs_intr_hard(int irq, void *dev_instance)
return IRQ_HANDLED;
}
-static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
+u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
{
unsigned int i, handled = 0;
@@ -1842,6 +1842,7 @@ static u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
return handled;
}
+EXPORT_SYMBOL_GPL(ahci_handle_port_intr);
static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance)
{
@@ -2466,13 +2467,19 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
{
struct ahci_host_priv *hpriv = host->private_data;
int irq = hpriv->irq;
+ irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);
int rc;
if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
rc = ahci_host_activate_multi_irqs(host, sht);
- else
- rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
+ else {
+ ahci_irq_handler = hpriv->ahci_irq_intr ? hpriv->ahci_irq_intr :
+ ahci_single_level_irq_intr;
+
+ rc = ata_host_activate(host, irq, ahci_irq_handler,
IRQF_SHARED, sht);
+ }
+
return rc;
}
EXPORT_SYMBOL_GPL(ahci_host_activate);
--
1.7.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler.
2016-01-27 9:49 ` [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler Suman Tripathi
@ 2016-01-31 11:35 ` Tejun Heo
2016-02-01 19:43 ` Suman Tripathi
0 siblings, 1 reply; 8+ messages in thread
From: Tejun Heo @ 2016-01-31 11:35 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Jan 27, 2016 at 03:19:56PM +0530, Suman Tripathi wrote:
> @@ -2466,13 +2467,19 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
> {
> struct ahci_host_priv *hpriv = host->private_data;
> int irq = hpriv->irq;
> + irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);
> int rc;
>
> if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
> rc = ahci_host_activate_multi_irqs(host, sht);
You need to add { } to the if body too. Please read CodingStyle.
> - else
> - rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
> + else {
> + ahci_irq_handler = hpriv->ahci_irq_intr ? hpriv->ahci_irq_intr :
> + ahci_single_level_irq_intr;
> +
> + rc = ata_host_activate(host, irq, ahci_irq_handler,
> IRQF_SHARED, sht);
> + }
Can you please make this handled the same way as ->start_engine?
Also, maybe print out a warning message if a driver specifies both
AHCI_HFLAG_MULTI_MSI[X] and the irq handler override?
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler.
2016-01-31 11:35 ` Tejun Heo
@ 2016-02-01 19:43 ` Suman Tripathi
0 siblings, 0 replies; 8+ messages in thread
From: Suman Tripathi @ 2016-02-01 19:43 UTC (permalink / raw)
To: linux-arm-kernel
On Sun, Jan 31, 2016 at 3:35 AM, Tejun Heo <htejun@gmail•com> wrote:
> On Wed, Jan 27, 2016 at 03:19:56PM +0530, Suman Tripathi wrote:
>> @@ -2466,13 +2467,19 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
>> {
>> struct ahci_host_priv *hpriv = host->private_data;
>> int irq = hpriv->irq;
>> + irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);
>> int rc;
>>
>> if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
>> rc = ahci_host_activate_multi_irqs(host, sht);
>
> You need to add { } to the if body too. Please read CodingStyle.
>
>> - else
>> - rc = ata_host_activate(host, irq, ahci_single_level_irq_intr,
>> + else {
>> + ahci_irq_handler = hpriv->ahci_irq_intr ? hpriv->ahci_irq_intr :
>> + ahci_single_level_irq_intr;
>> +
>> + rc = ata_host_activate(host, irq, ahci_irq_handler,
>> IRQF_SHARED, sht);
>> + }
>
> Can you please make this handled the same way as ->start_engine?
> Also, maybe print out a warning message if a driver specifies both
> AHCI_HFLAG_MULTI_MSI[X] and the irq handler override?
Ok Sure
>
> Thanks.
>
> --
> tejun
--
Thanks,
with regards,
Suman Tripathi
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2 3/3] ahci_xgene: Implement the workaround to fix the missing of edge interrupt for HOST_IRQ_STAT.
2016-01-27 9:49 [PATCH v2 0/3] ata: Fixes related to edge trigger latch for ahci_xgene driver Suman Tripathi
2016-01-27 9:49 ` [PATCH v2 1/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci Suman Tripathi
2016-01-27 9:49 ` [PATCH v2 2/3] libahci: Implement the capability to override the generic ahci interrupt handler Suman Tripathi
@ 2016-01-27 9:49 ` Suman Tripathi
2 siblings, 0 replies; 8+ messages in thread
From: Suman Tripathi @ 2016-01-27 9:49 UTC (permalink / raw)
To: linux-arm-kernel
Due to H/W errata, the HOST_IRQ_STAT register misses the edge interrupt
when clearing the HOST_IRQ_STAT register and hardware reporting the
PORT_IRQ_STAT register at the same clock cycle.
Signed-off-by: Suman Tripathi <stripathi@apm•com>
---
drivers/ata/ahci_xgene.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 84 insertions(+), 0 deletions(-)
diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c
index 892ec74..60076a3 100644
--- a/drivers/ata/ahci_xgene.c
+++ b/drivers/ata/ahci_xgene.c
@@ -548,6 +548,89 @@ softreset_retry:
return rc;
}
+/**
+ * xgene_ahci_handle_broken_edge_irq - Handle the broken irq.
+ * @ata_host: Host that recieved the irq
+ * @irq_masked: HOST_IRQ_STAT value
+ *
+ * For hardware with broken edge trigger latch
+ * the HOST_IRQ_STAT register misses the edge interrupt
+ * when clearing of HOST_IRQ_STAT register and hardware
+ * reporting the PORT_IRQ_STAT register at the
+ * same clock cycle.
+ * As such, the algorithm below outlines the workaround.
+ *
+ * 1. Read HOST_IRQ_STAT register and save the state.
+ * 2. Clear the HOST_IRQ_STAT register.
+ * 3. Read back the HOST_IRQ_STAT register.
+ * 4. If HOST_IRQ_STAT register equals to zero, then
+ * traverse the rest of port's PORT_IRQ_STAT register
+ * to check if an interrupt is triggered at that point else
+ * go to step 6.
+ * 5. If PORT_IRQ_STAT register of rest ports is not equal to zero
+ * then update the state of HOST_IRQ_STAT saved in step 1.
+ * 6. Handle port interrupts.
+ * 7. Exit
+ */
+static int xgene_ahci_handle_broken_edge_irq(struct ata_host *host,
+ u32 irq_masked)
+{
+ struct ahci_host_priv *hpriv = host->private_data;
+ void __iomem *port_mmio;
+ int i;
+
+ if (!readl(hpriv->mmio + HOST_IRQ_STAT)) {
+ for (i = 0; i < host->n_ports; i++) {
+ if (irq_masked & (1 << i))
+ continue;
+
+ port_mmio = ahci_port_base(host->ports[i]);
+ if (readl(port_mmio + PORT_IRQ_STAT))
+ irq_masked |= (1 << i);
+ }
+ }
+
+ return ahci_handle_port_intr(host, irq_masked);
+}
+
+static irqreturn_t xgene_ahci_irq_intr(int irq, void *dev_instance)
+{
+ struct ata_host *host = dev_instance;
+ struct ahci_host_priv *hpriv;
+ unsigned int rc = 0;
+ void __iomem *mmio;
+ u32 irq_stat, irq_masked;
+
+ VPRINTK("ENTER\n");
+
+ hpriv = host->private_data;
+ mmio = hpriv->mmio;
+
+ /* sigh. 0xffffffff is a valid return from h/w */
+ irq_stat = readl(mmio + HOST_IRQ_STAT);
+ if (!irq_stat)
+ return IRQ_NONE;
+
+ irq_masked = irq_stat & hpriv->port_map;
+
+ spin_lock(&host->lock);
+
+ /*
+ * HOST_IRQ_STAT behaves as edge triggered latch meaning that
+ * it should be cleared before all the port events are cleared.
+ */
+ writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+ rc = xgene_ahci_handle_broken_edge_irq(host, irq_masked);
+
+ spin_unlock(&host->lock);
+
+ VPRINTK("EXIT\n");
+
+ return IRQ_RETVAL(rc);
+
+}
+
static struct ata_port_operations xgene_ahci_v1_ops = {
.inherits = &ahci_ops,
.host_stop = xgene_ahci_host_stop,
@@ -780,6 +863,7 @@ skip_clk_phy:
break;
case XGENE_AHCI_V2:
hpriv->flags |= AHCI_HFLAG_YES_FBS;
+ hpriv->ahci_irq_intr = xgene_ahci_irq_intr;
break;
default:
break;
--
1.7.1
^ permalink raw reply related [flat|nested] 8+ messages in thread