* [PATCH v4 1/3] libahci: Implement the capability to override the generic ahci interrupt handler.
2016-02-06 5:55 [PATCH v4 0/3] ata: Fixes related to edge trigger latch for the ahci_xgene_driver suman Tripathi
@ 2016-02-06 5:55 ` suman Tripathi
2016-02-06 5:55 ` [PATCH v4 2/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci suman Tripathi
` (2 subsequent siblings)
3 siblings, 0 replies; 10+ messages in thread
From: suman Tripathi @ 2016-02-06 5:55 UTC (permalink / raw)
To: olof, tj, arnd
Cc: linux-ide, devicetree, linux-arm-kernel, mlangsdo, jcm, patches,
Suman Tripathi
From: Suman Tripathi <stripathi@apm.com>
This patch implements the capability to override the generic AHCI
interrupt handler so that the LDD drivers can implement their own
custom interrupt handler routines.
Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
drivers/ata/ahci.h | 2 ++
drivers/ata/libahci.c | 29 +++++++++++++++++++++--------
2 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index a4faa43..e64bdad 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -360,6 +360,7 @@ struct ahci_host_priv {
* be overridden anytime before the host is activated.
*/
void (*start_engine)(struct ata_port *ap);
+ irqreturn_t (*ahci_irq_handler)(int irq, void *dev_instance);
};
#ifdef CONFIG_PCI_MSI
@@ -423,6 +424,7 @@ 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 eda3cf2..d45a7a5 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -113,6 +113,9 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
const char *buf, size_t size);
static ssize_t ahci_show_em_supported(struct device *dev,
struct device_attribute *attr, char *buf);
+static irqreturn_t ahci_single_edge_irq_intr(int irq, void *dev_instance);
+
+static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance);
static DEVICE_ATTR(ahci_host_caps, S_IRUGO, ahci_show_host_caps, NULL);
static DEVICE_ATTR(ahci_host_cap2, S_IRUGO, ahci_show_host_cap2, NULL);
@@ -512,6 +515,11 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
if (!hpriv->start_engine)
hpriv->start_engine = ahci_start_engine;
+
+ if (!hpriv->ahci_irq_handler)
+ hpriv->ahci_irq_handler = (hpriv->flags & AHCI_HFLAG_EDGE_IRQ) ?
+ ahci_single_edge_irq_intr :
+ ahci_single_level_irq_intr;
}
EXPORT_SYMBOL_GPL(ahci_save_initial_config);
@@ -1816,7 +1824,7 @@ 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 +1850,7 @@ 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_edge_irq_intr(int irq, void *dev_instance)
{
@@ -2505,14 +2514,18 @@ int ahci_host_activate(struct ata_host *host, struct scsi_host_template *sht)
int irq = hpriv->irq;
int rc;
- if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX))
+ if (hpriv->flags & (AHCI_HFLAG_MULTI_MSI | AHCI_HFLAG_MULTI_MSIX)) {
+ if (hpriv->ahci_irq_handler)
+ dev_warn(host->dev, "both AHCI_HFLAG_MULTI_MSI flag set \
+ and custom irq handler implemented\n");
+
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);
+ } else {
+ rc = ata_host_activate(host, irq, hpriv->ahci_irq_handler,
+ IRQF_SHARED, sht);
+ }
+
+
return rc;
}
EXPORT_SYMBOL_GPL(ahci_host_activate);
--
1.7.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v4 2/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci.
2016-02-06 5:55 [PATCH v4 0/3] ata: Fixes related to edge trigger latch for the ahci_xgene_driver suman Tripathi
2016-02-06 5:55 ` [PATCH v4 1/3] libahci: Implement the capability to override the generic ahci interrupt handler suman Tripathi
@ 2016-02-06 5:55 ` suman Tripathi
2016-02-06 5:55 ` [PATCH v4 3/3] ahci_xgene: Implement the workaround to fix the missing of the edge interrupt for the HOST_IRQ_STAT suman Tripathi
[not found] ` <1454738124-9351-1-git-send-email-stripathi-qTEPVZfXA3Y@public.gmane.org>
3 siblings, 0 replies; 10+ messages in thread
From: suman Tripathi @ 2016-02-06 5:55 UTC (permalink / raw)
To: olof, tj, arnd
Cc: linux-ide, devicetree, linux-arm-kernel, mlangsdo, jcm, patches,
Suman Tripathi
From: Suman Tripathi <stripathi@apm.com>
This patch removes the AHCI_HFLAG_EDGE_IRQ support from libahci.
The flexibility to override the irq handles in the LLD's are
already present, so 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 | 40 +++++++++++++++++++++++++++++++++++++++-
drivers/ata/libahci.c | 43 +------------------------------------------
3 files changed, 41 insertions(+), 45 deletions(-)
diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index e64bdad..89d146e 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..38cbabd 100644
--- a/drivers/ata/ahci_xgene.c
+++ b/drivers/ata/ahci_xgene.c
@@ -548,6 +548,43 @@ softreset_retry:
return rc;
}
+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 = ahci_handle_port_intr(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,
@@ -779,7 +816,8 @@ 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;
+ hpriv->ahci_irq_handler = xgene_ahci_irq_intr;
break;
default:
break;
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index d45a7a5..c64f0db 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -113,8 +113,6 @@ static ssize_t ahci_store_em_buffer(struct device *dev,
const char *buf, size_t size);
static ssize_t ahci_show_em_supported(struct device *dev,
struct device_attribute *attr, char *buf);
-static irqreturn_t ahci_single_edge_irq_intr(int irq, void *dev_instance);
-
static irqreturn_t ahci_single_level_irq_intr(int irq, void *dev_instance);
static DEVICE_ATTR(ahci_host_caps, S_IRUGO, ahci_show_host_caps, NULL);
@@ -517,9 +515,7 @@ void ahci_save_initial_config(struct device *dev, struct ahci_host_priv *hpriv)
hpriv->start_engine = ahci_start_engine;
if (!hpriv->ahci_irq_handler)
- hpriv->ahci_irq_handler = (hpriv->flags & AHCI_HFLAG_EDGE_IRQ) ?
- ahci_single_edge_irq_intr :
- ahci_single_level_irq_intr;
+ hpriv->ahci_irq_handler = ahci_single_level_irq_intr;
}
EXPORT_SYMBOL_GPL(ahci_save_initial_config);
@@ -1852,43 +1848,6 @@ u32 ahci_handle_port_intr(struct ata_host *host, u32 irq_masked)
}
EXPORT_SYMBOL_GPL(ahci_handle_port_intr);
-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;
--
1.7.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v4 3/3] ahci_xgene: Implement the workaround to fix the missing of the edge interrupt for the HOST_IRQ_STAT.
2016-02-06 5:55 [PATCH v4 0/3] ata: Fixes related to edge trigger latch for the ahci_xgene_driver suman Tripathi
2016-02-06 5:55 ` [PATCH v4 1/3] libahci: Implement the capability to override the generic ahci interrupt handler suman Tripathi
2016-02-06 5:55 ` [PATCH v4 2/3] ata: Remove the AHCI_HFLAG_EDGE_IRQ support from libahci suman Tripathi
@ 2016-02-06 5:55 ` suman Tripathi
[not found] ` <1454738124-9351-1-git-send-email-stripathi-qTEPVZfXA3Y@public.gmane.org>
3 siblings, 0 replies; 10+ messages in thread
From: suman Tripathi @ 2016-02-06 5:55 UTC (permalink / raw)
To: olof, tj, arnd
Cc: linux-ide, devicetree, linux-arm-kernel, mlangsdo, jcm, patches,
Suman Tripathi
From: Suman Tripathi <stripathi@apm.com>
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 happens to be at the same clock cycle.
Signed-off-by: Suman Tripathi <stripathi@apm.com>
---
drivers/ata/ahci_xgene.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 46 insertions(+), 1 deletions(-)
diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c
index 38cbabd..2fc6b38 100644
--- a/drivers/ata/ahci_xgene.c
+++ b/drivers/ata/ahci_xgene.c
@@ -548,6 +548,51 @@ 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;
@@ -576,7 +621,7 @@ static irqreturn_t xgene_ahci_irq_intr(int irq, void *dev_instance)
*/
writel(irq_stat, mmio + HOST_IRQ_STAT);
- rc = ahci_handle_port_intr(host, irq_masked);
+ rc = xgene_ahci_handle_broken_edge_irq(host, irq_masked);
spin_unlock(&host->lock);
--
1.7.1
^ permalink raw reply related [flat|nested] 10+ messages in thread[parent not found: <1454738124-9351-1-git-send-email-stripathi-qTEPVZfXA3Y@public.gmane.org>]
* Re: [PATCH v4 0/3] ata: Fixes related to edge trigger latch for the ahci_xgene_driver.
[not found] ` <1454738124-9351-1-git-send-email-stripathi-qTEPVZfXA3Y@public.gmane.org>
@ 2016-02-10 16:25 ` Tejun Heo
[not found] ` <20160210162547.GJ3741-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
0 siblings, 1 reply; 10+ messages in thread
From: Tejun Heo @ 2016-02-10 16:25 UTC (permalink / raw)
To: suman Tripathi
Cc: olof-nZhT3qVonbNeoWH0uzbU5w, arnd-r2nGTMty4D4,
linux-ide-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
mlangsdo-H+wXaHxf7aLQT0dZR+AlfA, jcm-H+wXaHxf7aLQT0dZR+AlfA,
patches-qTEPVZfXA3Y
On Sat, Feb 06, 2016 at 11:25:21AM +0530, suman Tripathi wrote:
> From: Suman Tripathi <stripathi-qTEPVZfXA3Y@public.gmane.org>
>
> This patch set implements a workaround for an errate in the APM
> X-Gene SATA host controller with edge interrupt. The HOST_IRQ_STAT
> misses the edge interrupt from the PORT_IRQ_STAT when clearing the
> HOST_IRQ_STAT and reporting the PORT_IRQ_STAT happens in same clock
> cycle. It also implements the capability to override generic interrupt
> handler.
Applied 1-3 to libata/for-4.6 with minor updates.
Thanks.
--
tejun
--
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^ permalink raw reply [flat|nested] 10+ messages in thread