From 7551c40d908b2f6c08eb13571be1f9cfd7228689 Mon Sep 17 00:00:00 2001 From: Qiang Liu Date: Mon, 4 Mar 2013 15:20:23 +0800 Subject: [PATCH] fsl/sata: create a sysfs entry for rx water mark 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 Signed-off-by: Jeff Garzik --- drivers/ata/sata_fsl.c | 55 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c index 608f82fed632..d314c1dad069 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: @@ -1522,6 +1576,7 @@ 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); -- 2.20.1