[PATCH 2/3] spi: Use consistent MODALIAS values.

[David Daney <ddaney.cavm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>

For SPI devices, the MODALIAS should start with "spi:" so that the
modprobe can find the proper drivers.

Be consistent, for devices added via spi_new_device(), make sure
"spi:" is added if it is not already there.  In spi_match_device()
handle matching when the "spi:" prefix is present.

Signed-off-by: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>
---
 drivers/spi/spi.c |   39 ++++++++++++++++++++++++++++++++++-----
 1 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 3d8f662..8c49964 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -59,6 +59,16 @@ static struct device_attribute spi_dev_attrs[] = {
 	__ATTR_NULL,
 };
 
+/*
+ * modalias will be of the form "spi:name" or "name", match on just
+ * the name portion.
+ */
+static const char *spi_device_spidev2name(const struct spi_device *sdev)
+{
+	const char *p = strchr(sdev->modalias, ':');
+	return p ? p + 1 : sdev->modalias;
+}
+
 /* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
  * and the sysfs version makes coldplug work too.
  */
@@ -66,8 +76,10 @@ static struct device_attribute spi_dev_attrs[] = {
 static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
 						const struct spi_device *sdev)
 {
+	const char *name = spi_device_spidev2name(sdev);
+
 	while (id->name[0]) {
-		if (!strcmp(sdev->modalias, id->name))
+		if (!strcmp(name, id->name))
 			return id;
 		id++;
 	}
@@ -94,14 +106,20 @@ static int spi_match_device(struct device *dev, struct device_driver *drv)
 	if (sdrv->id_table)
 		return !!spi_match_id(sdrv->id_table, spi);
 
-	return strcmp(spi->modalias, drv->name) == 0;
+	return strcmp(spi_device_spidev2name(spi), drv->name) == 0;
 }
 
 static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	const struct spi_device		*spi = to_spi_device(dev);
 
-	add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
+	if (strncmp(SPI_MODULE_PREFIX, spi->modalias,
+		    strlen(SPI_MODULE_PREFIX)) == 0)
+		add_uevent_var(env, "MODALIAS=%s", spi->modalias);
+	else
+		add_uevent_var(env, "MODALIAS=%s%s",
+			       SPI_MODULE_PREFIX, spi->modalias);
+
 	return 0;
 }
 
@@ -418,6 +436,7 @@ struct spi_device *spi_new_device(struct spi_master *master,
 {
 	struct spi_device	*proxy;
 	int			status;
+	size_t			l;
 
 	/* NOTE:  caller did any chip->bus_num checks necessary.
 	 *
@@ -430,13 +449,23 @@ struct spi_device *spi_new_device(struct spi_master *master,
 	if (!proxy)
 		return NULL;
 
-	WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
+	if (strncmp(SPI_MODULE_PREFIX, chip->modalias,
+		    strlen(SPI_MODULE_PREFIX)) == 0) {
+		proxy->modalias[0] = 0;
+	} else {
+		l = strlcpy(proxy->modalias, SPI_MODULE_PREFIX,
+			    sizeof(proxy->modalias));
+		WARN_ON(l >= sizeof(proxy->modalias));
+	}
+
+	l = strlcat(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
+
+	WARN_ON(l >= sizeof(proxy->modalias));
 
 	proxy->chip_select = chip->chip_select;
 	proxy->max_speed_hz = chip->max_speed_hz;
 	proxy->mode = chip->mode;
 	proxy->irq = chip->irq;
-	strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
 	proxy->dev.platform_data = (void *) chip->platform_data;
 	proxy->controller_data = chip->controller_data;
 	proxy->controller_state = NULL;
-- 
1.7.2.3


------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/