From: Madhusudhan Chikkature <[EMAIL PROTECTED]>
This patch moves the shared variable into the local structure and
protects its updation.
Signed-off-by: Madhusudhan Chikkature <[EMAIL PROTECTED]>
---
drivers/w1/masters/omap_hdq.c | 52 ++++++++++++++++++++++++++++++------------
1 files changed, 38 insertions(+), 14 deletions(-)
Index: linux-omap-2.6/drivers/w1/masters/omap_hdq.c
===================================================================
--- linux-omap-2.6.orig/drivers/w1/masters/omap_hdq.c 2008-09-24
11:49:45.000000000 +0530
+++ linux-omap-2.6/drivers/w1/masters/omap_hdq.c 2008-09-24
14:41:43.000000000 +0530
@@ -61,6 +61,12 @@ struct hdq_data {
struct clk *hdq_fck;
u8 hdq_irqstatus;
spinlock_t hdq_spinlock;
+ /*
+ * Used to control the call to omap_hdq_get and omap_hdq_put.
+ * HDQ Protocol: Write the CMD|REG_address first, followed by
+ * the data wrire or read.
+ */
+ int init_trans;
};
static int omap_hdq_get(struct hdq_data *hdq_data);
@@ -505,13 +511,6 @@ omap_hdq_put(struct hdq_data *hdq_data)
}
/*
- * Used to control the call to omap_hdq_get and omap_hdq_put.
- * HDQ Protocol: Write the CMD|REG_address first, followed by
- * the data wrire or read.
- */
-static int init_trans;
-
-/*
* Read a byte of data from the device.
*/
static u8 omap_w1_read_byte(void *_hdq)
@@ -522,14 +521,26 @@ static u8 omap_w1_read_byte(void *_hdq)
ret = hdq_read_byte(hdq_data, &val);
if (ret) {
- init_trans = 0;
+ ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
+ if (ret < 0) {
+ dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
+ return -EINTR;
+ }
+ hdq_data->init_trans = 0;
+ mutex_unlock(&hdq_data->hdq_mutex);
omap_hdq_put(hdq_data);
return -1;
}
/* Write followed by a read, release the module */
- if (init_trans) {
- init_trans = 0;
+ if (hdq_data->init_trans) {
+ ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
+ if (ret < 0) {
+ dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
+ return -EINTR;
+ }
+ hdq_data->init_trans = 0;
+ mutex_unlock(&hdq_data->hdq_mutex);
omap_hdq_put(hdq_data);
}
@@ -542,21 +553,34 @@ static u8 omap_w1_read_byte(void *_hdq)
static void omap_w1_write_byte(void *_hdq, u8 byte)
{
struct hdq_data *hdq_data = _hdq;
+ int ret;
u8 status;
/* First write to initialize the transfer */
- if (init_trans == 0)
+ if (hdq_data->init_trans == 0)
omap_hdq_get(hdq_data);
- init_trans++;
+ ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
+ if (ret < 0) {
+ dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
+ return;
+ }
+ hdq_data->init_trans++;
+ mutex_unlock(&hdq_data->hdq_mutex);
hdq_write_byte(hdq_data, byte, &status);
dev_dbg(hdq_data->dev, "Ctrl status %x\n", status);
/* Second write, data transfered. Release the module */
- if (init_trans > 1) {
+ if (hdq_data->init_trans > 1) {
omap_hdq_put(hdq_data);
- init_trans = 0;
+ ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
+ if (ret < 0) {
+ dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
+ return;
+ }
+ hdq_data->init_trans = 0;
+ mutex_unlock(&hdq_data->hdq_mutex);
}
return;--
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