Patchwork fsl/sata: create a sysfs entry for rx water mark

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Submitter Qiang Liu
Date March 4, 2013, 7:20 a.m.
Message ID <1362381623-10856-1-git-send-email-qiang.liu@freescale.com>
Download mbox | patch
Permalink /patch/224606/
State Not Applicable
Delegated to: Kumar Gala
Headers show

Comments

Qiang Liu - March 4, 2013, 7:20 a.m.
Support config RX WATER MARK via sysfs when running at run-time;
A wrokaround for fix the exception happened to some WD HDD, found on
WD3000HLFS-01G6U1, WD3000HLFS-01G6U0, some SSD disks. The read performance
is also regression (about 30%) when use default value.

According to the latest documents, 0x10 is the default value of RX WATER MARK,
but exception/performance issue happened to some disks mentioned above.

The exception log as below when testing read performance with IOZone:
ata1.00: exception Emask 0x0 SAct 0x7 SErr 0x800000 action 0x6 frozen
ata1: SError: { LinkSeq }
ata1.00: failed command: READ FPDMA QUEUED
ata1.00: cmd 60/00:00:ff:2c:14/01:00:02:00:00/40 tag 0 ncq 131072 in
res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1.00: failed command: READ FPDMA QUEUED
ata1.00: cmd 60/00:08:ff:2d:14/01:00:02:00:00/40 tag 1 ncq 131072 in
res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1.00: failed command: WRITE FPDMA QUEUED
ata1.00: cmd 61/10:10:af:08:6e/00:00:12:00:00/40 tag 2 ncq 8192 out
res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
ata1.00: status: { DRDY }
ata1: hard resetting link
ata1: Hardreset failed, not off-lined 0
ata1: Signature Update detected @ 504 msecs
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1.00: configured for UDMA/133
ata1.00: device reported invalid CHS sector 0
ata1.00: device reported invalid CHS sector 0
ata1.00: device reported invalid CHS sector 0
ata1: EH complete

The exception/performance can be resolved when RX WATER MARK value is 0x16.

Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
---
 drivers/ata/sata_fsl.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 55 insertions(+), 0 deletions(-)

--
1.7.5.1
Jeff Garzik - April 3, 2013, 11:57 p.m.
On 03/04/2013 02:20 AM, Qiang Liu wrote:
> Support config RX WATER MARK via sysfs when running at run-time;
> A wrokaround for fix the exception happened to some WD HDD, found on
> WD3000HLFS-01G6U1, WD3000HLFS-01G6U0, some SSD disks. The read performance
> is also regression (about 30%) when use default value.
>
> According to the latest documents, 0x10 is the default value of RX WATER MARK,
> but exception/performance issue happened to some disks mentioned above.
>
> The exception log as below when testing read performance with IOZone:
> ata1.00: exception Emask 0x0 SAct 0x7 SErr 0x800000 action 0x6 frozen
> ata1: SError: { LinkSeq }
> ata1.00: failed command: READ FPDMA QUEUED
> ata1.00: cmd 60/00:00:ff:2c:14/01:00:02:00:00/40 tag 0 ncq 131072 in
> res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
> ata1.00: status: { DRDY }
> ata1.00: failed command: READ FPDMA QUEUED
> ata1.00: cmd 60/00:08:ff:2d:14/01:00:02:00:00/40 tag 1 ncq 131072 in
> res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
> ata1.00: status: { DRDY }
> ata1.00: failed command: WRITE FPDMA QUEUED
> ata1.00: cmd 61/10:10:af:08:6e/00:00:12:00:00/40 tag 2 ncq 8192 out
> res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout)
> ata1.00: status: { DRDY }
> ata1: hard resetting link
> ata1: Hardreset failed, not off-lined 0
> ata1: Signature Update detected @ 504 msecs
> ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
> ata1.00: configured for UDMA/133
> ata1.00: device reported invalid CHS sector 0
> ata1.00: device reported invalid CHS sector 0
> ata1.00: device reported invalid CHS sector 0
> ata1: EH complete
>
> The exception/performance can be resolved when RX WATER MARK value is 0x16.
>
> Signed-off-by: Qiang Liu <qiang.liu@freescale.com>
> ---
>   drivers/ata/sata_fsl.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 55 insertions(+), 0 deletions(-)

applied, though it seems advisable to simply set 0x16 than all this mess

Patch

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index 124b2c1..515f66f 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -285,6 +285,7 @@  struct sata_fsl_host_priv {
 	int irq;
 	int data_snoop;
 	struct device_attribute intr_coalescing;
+	struct device_attribute rx_watermark;
 };

 static void fsl_sata_set_irq_coalescing(struct ata_host *host,
@@ -343,6 +344,48 @@  static ssize_t fsl_sata_intr_coalescing_store(struct device *dev,
 	return strlen(buf);
 }

+static ssize_t fsl_sata_rx_watermark_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	unsigned int rx_watermark;
+	unsigned long flags;
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct sata_fsl_host_priv *host_priv = host->private_data;
+	void __iomem *csr_base = host_priv->csr_base;
+
+	spin_lock_irqsave(&host->lock, flags);
+	rx_watermark = ioread32(csr_base + TRANSCFG);
+	rx_watermark &= 0x1f;
+
+	spin_unlock_irqrestore(&host->lock, flags);
+	return sprintf(buf, "%d\n", rx_watermark);
+}
+
+static ssize_t fsl_sata_rx_watermark_store(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	unsigned int rx_watermark;
+	unsigned long flags;
+	struct ata_host *host = dev_get_drvdata(dev);
+	struct sata_fsl_host_priv *host_priv = host->private_data;
+	void __iomem *csr_base = host_priv->csr_base;
+	u32 temp;
+
+	if (sscanf(buf, "%d", &rx_watermark) != 1) {
+		printk(KERN_ERR "fsl-sata: wrong parameter format.\n");
+		return -EINVAL;
+	}
+
+	spin_lock_irqsave(&host->lock, flags);
+	temp = ioread32(csr_base + TRANSCFG);
+	temp &= 0xffffffe0;
+	iowrite32(temp | rx_watermark, csr_base + TRANSCFG);
+
+	spin_unlock_irqrestore(&host->lock, flags);
+	return strlen(buf);
+}
+
 static inline unsigned int sata_fsl_tag(unsigned int tag,
 					void __iomem *hcr_base)
 {
@@ -1500,6 +1543,17 @@  static int sata_fsl_probe(struct platform_device *ofdev)
 	if (retval)
 		goto error_exit_with_cleanup;

+	host_priv->rx_watermark.show = fsl_sata_rx_watermark_show;
+	host_priv->rx_watermark.store = fsl_sata_rx_watermark_store;
+	sysfs_attr_init(&host_priv->rx_watermark.attr);
+	host_priv->rx_watermark.attr.name = "rx_watermark";
+	host_priv->rx_watermark.attr.mode = S_IRUGO | S_IWUSR;
+	retval = device_create_file(host->dev, &host_priv->rx_watermark);
+	if (retval) {
+		device_remove_file(&ofdev->dev, &host_priv->intr_coalescing);
+		goto error_exit_with_cleanup;
+	}
+
 	return 0;

 error_exit_with_cleanup:
@@ -1523,6 +1577,7 @@  static int sata_fsl_remove(struct platform_device *ofdev)
 	struct sata_fsl_host_priv *host_priv = host->private_data;

 	device_remove_file(&ofdev->dev, &host_priv->intr_coalescing);
+	device_remove_file(&ofdev->dev, &host_priv->rx_watermark);

 	ata_host_detach(host);