On Thu, Sep 25, 2008 at 12:28:22PM +0530, ext Gadiyar, Anand wrote:
> From: Madhusudhan Chikkature <madhu.cr@xxxxxx>
>
> This patch moves the shared variable into the local structure and
> protects its updation.
>
> Signed-off-by: Madhusudhan Chikkature <madhu.cr@xxxxxx>
Acked-by: Felipe Balbi <felipe.balbi@xxxxxxxxx>
> ---
> 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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--
balbi
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