[patch] libata:ahci: enclosure management support (resend)

From: Kristen Carlson Accardi
Date: Tue Jun 03 2008 - 13:43:44 EST


Here's a resend of the patch I sent 2 weeks ago, refreshed against
Andrews kernel. This is one of many resends since the original
patch was sent in January-ish. Could you please review this patch
and let me know what you'd like me to change? I'm happy to change it
however you want as long as the feature still functions.

Thanks,
Kristen

Add Enclosure Management support to libata and ahci.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>
---
drivers/ata/ahci.c | 321 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/ata/libata-scsi.c | 79 +++++++++++
include/linux/libata.h | 21 +++
3 files changed, 419 insertions(+), 2 deletions(-)

Index: linux-em/drivers/ata/ahci.c
===================================================================
--- linux-em.orig/drivers/ata/ahci.c 2008-06-03 10:22:07.000000000 -0700
+++ linux-em/drivers/ata/ahci.c 2008-06-03 10:24:02.000000000 -0700
@@ -56,6 +56,12 @@ MODULE_PARM_DESC(skip_host_reset, "skip
static int ahci_enable_alpm(struct ata_port *ap,
enum link_pm policy);
static void ahci_disable_alpm(struct ata_port *ap);
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf);
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+ size_t size);
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+ ssize_t size);
+#define MAX_SLOTS 8

enum {
AHCI_PCI_BAR = 5,
@@ -96,6 +102,8 @@ enum {
HOST_IRQ_STAT = 0x08, /* interrupt status */
HOST_PORTS_IMPL = 0x0c, /* bitmap of implemented ports */
HOST_VERSION = 0x10, /* AHCI spec. version compliancy */
+ HOST_EM_LOC = 0x1c, /* Enclosure Management location */
+ HOST_EM_CTL = 0x20, /* Enclosure Management Control */

/* HOST_CTL bits */
HOST_RESET = (1 << 0), /* reset controller; self-clear */
@@ -103,6 +111,7 @@ enum {
HOST_AHCI_EN = (1 << 31), /* AHCI enabled */

/* HOST_CAP bits */
+ HOST_CAP_EMS = (1 << 6), /* Enclosure Management support */
HOST_CAP_SSC = (1 << 14), /* Slumber capable */
HOST_CAP_PMP = (1 << 17), /* Port Multiplier support */
HOST_CAP_CLO = (1 << 24), /* Command List Override support */
@@ -199,6 +208,11 @@ enum {
ATA_FLAG_IPM,

ICH_MAP = 0x90, /* ICH MAP register */
+
+ /* em_ctl bits */
+ EM_CTL_RST = (1 << 9), /* Reset */
+ EM_CTL_TM = (1 << 8), /* Transmit Message */
+ EM_CTL_ALHD = (1 << 26), /* Activity LED */
};

struct ahci_cmd_hdr {
@@ -216,12 +230,21 @@ struct ahci_sg {
__le32 flags_size;
};

+struct ahci_em_priv {
+ enum sw_activity blink_policy;
+ struct timer_list timer;
+ unsigned long saved_activity;
+ unsigned long activity;
+ unsigned long led_state;
+};
+
struct ahci_host_priv {
unsigned int flags; /* AHCI_HFLAG_* */
u32 cap; /* cap to use */
u32 port_map; /* port map to use */
u32 saved_cap; /* saved initial cap */
u32 saved_port_map; /* saved initial port_map */
+ u32 em_loc; /* enclosure management location */
};

struct ahci_port_priv {
@@ -237,6 +260,8 @@ struct ahci_port_priv {
unsigned int ncq_saw_dmas:1;
unsigned int ncq_saw_sdb:1;
u32 intr_mask; /* interrupts to enable */
+ struct ahci_em_priv em_priv[MAX_SLOTS];/* enclosure management info
+ * per PM slot */
};

static int ahci_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
@@ -272,9 +297,20 @@ static int ahci_port_suspend(struct ata_
static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
static int ahci_pci_device_resume(struct pci_dev *pdev);
#endif
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf);
+static ssize_t ahci_activity_store(struct ata_device *dev,
+ enum sw_activity val);
+static void ahci_init_sw_activity(struct ata_link *link);

static struct device_attribute *ahci_shost_attrs[] = {
&dev_attr_link_power_management_policy,
+ &dev_attr_em_message_type,
+ &dev_attr_em_message,
+ NULL
+};
+
+static struct device_attribute *ahci_sdev_attrs[] = {
+ &dev_attr_sw_activity,
NULL
};

@@ -284,6 +320,7 @@ static struct scsi_host_template ahci_sh
.sg_tablesize = AHCI_MAX_SG,
.dma_boundary = AHCI_DMA_BOUNDARY,
.shost_attrs = ahci_shost_attrs,
+ .sdev_attrs = ahci_sdev_attrs,
};

static struct ata_port_operations ahci_ops = {
@@ -311,6 +348,10 @@ static struct ata_port_operations ahci_o

.enable_pm = ahci_enable_alpm,
.disable_pm = ahci_disable_alpm,
+ .em_show = ahci_led_show,
+ .em_store = ahci_led_store,
+ .sw_activity_show = ahci_activity_show,
+ .sw_activity_store = ahci_activity_store,
#ifdef CONFIG_PM
.port_suspend = ahci_port_suspend,
.port_resume = ahci_port_resume,
@@ -535,6 +576,11 @@ static struct pci_driver ahci_pci_driver
#endif
};

+static int ahci_em_messages = 1;
+module_param(ahci_em_messages, int, 0444);
+/* add other LED protocol types when they become supported */
+MODULE_PARM_DESC(ahci_em_messages,
+ "Set AHCI Enclosure Management Message type (0 = disabled, 1 = LED");

static inline int ahci_nr_ports(u32 cap)
{
@@ -991,11 +1037,28 @@ static void ahci_power_down(struct ata_p

static void ahci_start_port(struct ata_port *ap)
{
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ata_link *link;
+ struct ahci_em_priv *emp;
+
/* enable FIS reception */
ahci_start_fis_rx(ap);

/* enable DMA */
ahci_start_engine(ap);
+
+ /* turn on LEDs */
+ if (ap->flags & ATA_FLAG_EM) {
+ ata_port_for_each_link(link, ap) {
+ emp = &pp->em_priv[link->pmp];
+ ahci_transmit_led_message(ap, emp->led_state, 4);
+ }
+ }
+
+ if (ap->flags & ATA_FLAG_SW_ACTIVITY)
+ ata_port_for_each_link(link, ap)
+ ahci_init_sw_activity(link);
+
}

static int ahci_deinit_port(struct ata_port *ap, const char **emsg)
@@ -1076,6 +1139,230 @@ static int ahci_reset_controller(struct
return 0;
}

+static void ahci_sw_activity(struct ata_link *link)
+{
+ struct ata_port *ap = link->ap;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+ if (!(link->flags & ATA_LFLAG_SW_ACTIVITY))
+ return;
+
+ emp->activity++;
+ if (!timer_pending(&emp->timer))
+ mod_timer(&emp->timer, jiffies + msecs_to_jiffies(10));
+}
+
+static void ahci_sw_activity_blink(unsigned long arg)
+{
+ struct ata_link *link = (struct ata_link *)arg;
+ struct ata_port *ap = link->ap;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+ unsigned long led_message = emp->led_state;
+ u32 activity_led_state;
+
+ led_message &= 0xffff0000;
+ led_message |= ap->port_no | (link->pmp << 8);
+
+ /* check to see if we've had activity. If so,
+ * toggle state of LED and reset timer. If not,
+ * turn LED to desired idle state.
+ */
+ if (emp->saved_activity != emp->activity) {
+ emp->saved_activity = emp->activity;
+ /* get the current LED state */
+ activity_led_state = led_message & 0x00010000;
+
+ if (activity_led_state)
+ activity_led_state = 0;
+ else
+ activity_led_state = 1;
+
+ /* clear old state */
+ led_message &= 0xfff8ffff;
+
+ /* toggle state */
+ led_message |= (activity_led_state << 16);
+ mod_timer(&emp->timer, jiffies + msecs_to_jiffies(100));
+ } else {
+ /* switch to idle */
+ led_message &= 0xfff8ffff;
+ if (emp->blink_policy == BLINK_OFF)
+ led_message |= (1 << 16);
+ }
+ ahci_transmit_led_message(ap, led_message, 4);
+}
+
+static void ahci_init_sw_activity(struct ata_link *link)
+{
+ struct ata_port *ap = link->ap;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+ /* init activity stats, setup timer */
+ emp->saved_activity = emp->activity = 0;
+ setup_timer(&emp->timer, ahci_sw_activity_blink, (unsigned long)link);
+
+ /* check our blink policy and set flag for link if it's enabled */
+ if (emp->blink_policy)
+ link->flags |= ATA_LFLAG_SW_ACTIVITY;
+}
+
+static int ahci_reset_em(struct ata_host *host)
+{
+ void __iomem *mmio = host->iomap[AHCI_PCI_BAR];
+ u32 em_ctl;
+
+ em_ctl = readl(mmio + HOST_EM_CTL);
+ if ((em_ctl & EM_CTL_TM) || (em_ctl & EM_CTL_RST))
+ return -EINVAL;
+
+ writel(em_ctl | EM_CTL_RST, mmio + HOST_EM_CTL);
+ return 0;
+}
+
+static ssize_t ahci_transmit_led_message(struct ata_port *ap, u32 state,
+ ssize_t size)
+{
+ struct ahci_host_priv *hpriv = ap->host->private_data;
+ struct ahci_port_priv *pp = ap->private_data;
+ void __iomem *mmio = ap->host->iomap[AHCI_PCI_BAR];
+ u32 em_ctl;
+ u32 message[] = {0, 0};
+ unsigned int flags;
+ int pmp;
+ struct ahci_em_priv *emp;
+
+ /* get the slot number from the message */
+ pmp = (state & 0x0000ff00) >> 8;
+ if (pmp < MAX_SLOTS)
+ emp = &pp->em_priv[pmp];
+ else
+ return -EINVAL;
+
+ spin_lock_irqsave(ap->lock, flags);
+
+ /*
+ * if we are still busy transmitting a previous message,
+ * do not allow
+ */
+ em_ctl = readl(mmio + HOST_EM_CTL);
+ if (em_ctl & EM_CTL_TM) {
+ spin_unlock_irqrestore(ap->lock, flags);
+ return -EINVAL;
+ }
+
+ /*
+ * create message header - this is all zero except for
+ * the message size, which is 4 bytes.
+ */
+ message[0] |= (4 << 8);
+
+ /* ignore 0:4 of byte zero, fill in port info yourself */
+ message[1] = ((state & 0xfffffff0) | ap->port_no);
+
+ /* write message to EM_LOC */
+ writel(message[0], mmio + hpriv->em_loc);
+ writel(message[1], mmio + hpriv->em_loc+4);
+
+ /* save off new led state for port/slot */
+ emp->led_state = message[1];
+
+ /*
+ * tell hardware to transmit the message
+ */
+ writel(em_ctl | EM_CTL_TM, mmio + HOST_EM_CTL);
+
+ spin_unlock_irqrestore(ap->lock, flags);
+ return size;
+}
+
+static ssize_t ahci_led_show(struct ata_port *ap, char *buf)
+{
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ata_link *link;
+ struct ahci_em_priv *emp;
+ int rc = 0;
+
+ ata_port_for_each_link(link, ap) {
+ emp = &pp->em_priv[link->pmp];
+ rc += sprintf(buf, "%lx\n", emp->led_state);
+ }
+ return rc;
+}
+
+static ssize_t ahci_led_store(struct ata_port *ap, const char *buf,
+ size_t size)
+{
+ int state;
+ int pmp;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp;
+
+ state = simple_strtoul(buf, NULL, 0);
+
+ /* get the slot number from the message */
+ pmp = (state & 0x0000ff00) >> 8;
+ if (pmp < MAX_SLOTS)
+ emp = &pp->em_priv[pmp];
+ else
+ return -EINVAL;
+
+ /* mask off the activity bits if we are in sw_activity
+ * mode, user should turn off sw_activity before setting
+ * activity led through em_message
+ */
+ if (emp->blink_policy)
+ state &= 0xfff8ffff;
+
+ return ahci_transmit_led_message(ap, state, size);
+}
+
+static ssize_t ahci_activity_store(struct ata_device *dev, enum sw_activity val)
+{
+ struct ata_link *link = dev->link;
+ struct ata_port *ap = link->ap;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+ u32 port_led_state = emp->led_state;
+
+ /* save the desired Activity LED behavior */
+ if (val == OFF) {
+ /* clear LFLAG */
+ link->flags &= ~(ATA_LFLAG_SW_ACTIVITY);
+
+ /* set the LED to OFF */
+ port_led_state &= 0xfff80000;
+ port_led_state |= (ap->port_no | (link->pmp << 8));
+ ahci_transmit_led_message(ap, port_led_state, 4);
+ } else {
+ link->flags |= ATA_LFLAG_SW_ACTIVITY;
+ if (val == BLINK_OFF) {
+ /* set LED to ON for idle */
+ port_led_state &= 0xfff80000;
+ port_led_state |= (ap->port_no | (link->pmp << 8));
+ port_led_state |= 0x00010000; /* check this */
+ ahci_transmit_led_message(ap, port_led_state, 4);
+ }
+ }
+ emp->blink_policy = val;
+ return 0;
+}
+
+static ssize_t ahci_activity_show(struct ata_device *dev, char *buf)
+{
+ struct ata_link *link = dev->link;
+ struct ata_port *ap = link->ap;
+ struct ahci_port_priv *pp = ap->private_data;
+ struct ahci_em_priv *emp = &pp->em_priv[link->pmp];
+
+ /* display the saved value of activity behavior for this
+ * disk.
+ */
+ return sprintf(buf, "%d\n", emp->blink_policy);
+}
+
static void ahci_port_init(struct pci_dev *pdev, struct ata_port *ap,
int port_no, void __iomem *mmio,
void __iomem *port_mmio)
@@ -1743,6 +2030,8 @@ static unsigned int ahci_qc_issue(struct
writel(1 << qc->tag, port_mmio + PORT_CMD_ISSUE);
readl(port_mmio + PORT_CMD_ISSUE); /* flush */

+ ahci_sw_activity(qc->dev->link);
+
return 0;
}

@@ -2049,7 +2338,8 @@ static void ahci_print_info(struct ata_h
dev_printk(KERN_INFO, &pdev->dev,
"flags: "
"%s%s%s%s%s%s%s"
- "%s%s%s%s%s%s%s\n"
+ "%s%s%s%s%s%s%s"
+ "%s\n"
,

cap & (1 << 31) ? "64bit " : "",
@@ -2066,7 +2356,8 @@ static void ahci_print_info(struct ata_h
cap & (1 << 17) ? "pmp " : "",
cap & (1 << 15) ? "pio " : "",
cap & (1 << 14) ? "slum " : "",
- cap & (1 << 13) ? "part " : ""
+ cap & (1 << 13) ? "part " : "",
+ cap & (1 << 6) ? "ems ": ""
);
}

@@ -2180,6 +2471,24 @@ static int ahci_init_one(struct pci_dev
if (hpriv->cap & HOST_CAP_PMP)
pi.flags |= ATA_FLAG_PMP;

+ if (ahci_em_messages && (hpriv->cap & HOST_CAP_EMS)) {
+ u8 messages;
+ void __iomem *mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR];
+ u32 em_loc = readl(mmio + HOST_EM_LOC);
+ u32 em_ctl = readl(mmio + HOST_EM_CTL);
+
+ messages = (em_ctl & 0x000f0000) >> 16;
+
+ /* we only support LED message type right now */
+ if ((messages & 0x01) && (ahci_em_messages == 1)) {
+ /* store em_loc */
+ hpriv->em_loc = ((em_loc >> 16) * 4);
+ pi.flags |= ATA_FLAG_EM;
+ if (!(em_ctl & EM_CTL_ALHD))
+ pi.flags |= ATA_FLAG_SW_ACTIVITY;
+ }
+ }
+
/* CAP.NP sometimes indicate the index of the last enabled
* port, at other times, that of the last possible port, so
* determining the maximum port number requires looking at
@@ -2193,6 +2502,9 @@ static int ahci_init_one(struct pci_dev
host->iomap = pcim_iomap_table(pdev);
host->private_data = hpriv;

+ if (pi.flags & ATA_FLAG_EM)
+ ahci_reset_em(host);
+
for (i = 0; i < host->n_ports; i++) {
struct ata_port *ap = host->ports[i];

@@ -2203,6 +2515,11 @@ static int ahci_init_one(struct pci_dev
/* set initial link pm policy */
ap->pm_policy = NOT_AVAILABLE;

+ /* set enclosure management message type */
+ if (ap->flags & ATA_FLAG_EM)
+ ap->em_message_type = ahci_em_messages;
+
+
/* disabled/not-implemented port */
if (!(hpriv->port_map & (1 << i)))
ap->ops = &ata_dummy_port_ops;
Index: linux-em/drivers/ata/libata-scsi.c
===================================================================
--- linux-em.orig/drivers/ata/libata-scsi.c 2008-06-03 10:22:07.000000000 -0700
+++ linux-em/drivers/ata/libata-scsi.c 2008-06-03 10:24:02.000000000 -0700
@@ -190,6 +190,85 @@ static void ata_scsi_set_sense(struct sc
scsi_build_sense_buffer(0, cmd->sense_buffer, sk, asc, ascq);
}

+static ssize_t
+ata_scsi_em_message_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct Scsi_Host *shost = class_to_shost(dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+ if (ap->ops->em_store && (ap->flags & ATA_FLAG_EM))
+ return ap->ops->em_store(ap, buf, count);
+ return -EINVAL;
+}
+
+static ssize_t
+ata_scsi_em_message_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+
+ if (ap->ops->em_show && (ap->flags & ATA_FLAG_EM))
+ return ap->ops->em_show(ap, buf);
+ return -EINVAL;
+}
+DEVICE_ATTR(em_message, S_IRUGO | S_IWUGO,
+ ata_scsi_em_message_show, ata_scsi_em_message_store);
+EXPORT_SYMBOL_GPL(dev_attr_em_message);
+
+static ssize_t
+ata_scsi_em_message_type_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct Scsi_Host *shost = class_to_shost(dev);
+ struct ata_port *ap = ata_shost_to_port(shost);
+
+ return snprintf(buf, 23, "%d\n", ap->em_message_type);
+}
+DEVICE_ATTR(em_message_type, S_IRUGO,
+ ata_scsi_em_message_type_show, NULL);
+EXPORT_SYMBOL_GPL(dev_attr_em_message_type);
+
+static ssize_t
+ata_scsi_activity_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ata_port *ap = ata_shost_to_port(sdev->host);
+ struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+
+ if (ap->ops->sw_activity_show && (ap->flags & ATA_FLAG_SW_ACTIVITY))
+ return ap->ops->sw_activity_show(atadev, buf);
+ return -EINVAL;
+}
+
+static ssize_t
+ata_scsi_activity_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct ata_port *ap = ata_shost_to_port(sdev->host);
+ struct ata_device *atadev = ata_scsi_find_dev(ap, sdev);
+ enum sw_activity val;
+ int rc;
+
+ if (ap->ops->sw_activity_store && (ap->flags & ATA_FLAG_SW_ACTIVITY)) {
+ val = simple_strtoul(buf, NULL, 0);
+ switch (val) {
+ case OFF: case BLINK_ON: case BLINK_OFF:
+ rc = ap->ops->sw_activity_store(atadev, val);
+ if (!rc)
+ return count;
+ else
+ return rc;
+ }
+ }
+ return -EINVAL;
+}
+DEVICE_ATTR(sw_activity, S_IWUGO | S_IRUGO, ata_scsi_activity_show,
+ ata_scsi_activity_store);
+EXPORT_SYMBOL_GPL(dev_attr_sw_activity);
+
static void ata_scsi_invalid_field(struct scsi_cmnd *cmd,
void (*done)(struct scsi_cmnd *))
{
Index: linux-em/include/linux/libata.h
===================================================================
--- linux-em.orig/include/linux/libata.h 2008-06-03 10:23:52.000000000 -0700
+++ linux-em/include/linux/libata.h 2008-06-03 10:24:02.000000000 -0700
@@ -171,6 +171,7 @@ enum {
ATA_LFLAG_ASSUME_CLASS = ATA_LFLAG_ASSUME_ATA | ATA_LFLAG_ASSUME_SEMB,
ATA_LFLAG_NO_RETRY = (1 << 5), /* don't retry this link */
ATA_LFLAG_DISABLED = (1 << 6), /* link is disabled */
+ ATA_LFLAG_SW_ACTIVITY = (1 << 7), /* keep activity stats */

/* struct ata_port flags */
ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */
@@ -193,6 +194,10 @@ enum {
ATA_FLAG_AN = (1 << 18), /* controller supports AN */
ATA_FLAG_PMP = (1 << 19), /* controller supports PMP */
ATA_FLAG_IPM = (1 << 20), /* driver can handle IPM */
+ ATA_FLAG_EM = (1 << 21), /* driver supports enclosure
+ * management */
+ ATA_FLAG_SW_ACTIVITY = (1 << 22), /* driver supports sw activity
+ * led */

/* The following flag belongs to ap->pflags but is kept in
* ap->flags because it's referenced in many LLDs and will be
@@ -444,6 +449,15 @@ enum link_pm {
MEDIUM_POWER,
};
extern struct device_attribute dev_attr_link_power_management_policy;
+extern struct device_attribute dev_attr_em_message_type;
+extern struct device_attribute dev_attr_em_message;
+extern struct device_attribute dev_attr_sw_activity;
+
+enum sw_activity {
+ OFF,
+ BLINK_ON,
+ BLINK_OFF,
+};

#ifdef CONFIG_ATA_SFF
struct ata_ioports {
@@ -695,6 +709,7 @@ struct ata_port {
struct timer_list fastdrain_timer;
unsigned long fastdrain_cnt;

+ int em_message_type;
void *private_data;

#ifdef CONFIG_ATA_ACPI
@@ -786,6 +801,12 @@ struct ata_port_operations {
u8 (*bmdma_status)(struct ata_port *ap);
#endif /* CONFIG_ATA_SFF */

+ ssize_t (*em_show)(struct ata_port *ap, char *buf);
+ ssize_t (*em_store)(struct ata_port *ap, const char *message,
+ size_t size);
+ ssize_t (*sw_activity_show)(struct ata_device *dev, char *buf);
+ ssize_t (*sw_activity_store)(struct ata_device *dev,
+ enum sw_activity val);
/*
* Obsolete
*/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/