[PATCH v2 1/7] soc: qcom: smd: Introduce callback setter

From: Bjorn Andersson
Date: Fri Oct 09 2015 - 16:50:25 EST


Introduce a setter for the callback function pointer to clarify the
locking around the operation and to reduce some duplication.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
---

Changes since v1:
- New patch

drivers/soc/qcom/smd.c | 25 +++++++++++++++++--------
include/linux/soc/qcom/smd.h | 4 +++-
2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c
index 18964f154383..8b401d89b0d0 100644
--- a/drivers/soc/qcom/smd.c
+++ b/drivers/soc/qcom/smd.c
@@ -186,7 +186,7 @@ struct qcom_smd_channel {
int fifo_size;

void *bounce_buffer;
- int (*cb)(struct qcom_smd_device *, const void *, size_t);
+ qcom_smd_cb_t cb;

spinlock_t recv_lock;

@@ -378,6 +378,19 @@ static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
}

/*
+ * Set the callback for a channel, with appropriate locking
+ */
+static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
+ qcom_smd_cb_t cb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&channel->recv_lock, flags);
+ channel->cb = cb;
+ spin_unlock_irqrestore(&channel->recv_lock, flags);
+};
+
+/*
* Calculate the amount of data available in the rx fifo
*/
static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
@@ -815,8 +828,7 @@ static int qcom_smd_dev_probe(struct device *dev)
if (!channel->bounce_buffer)
return -ENOMEM;

- channel->cb = qsdrv->callback;
-
+ qcom_smd_channel_set_callback(channel, qsdrv->callback);
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);

qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
@@ -832,7 +844,7 @@ static int qcom_smd_dev_probe(struct device *dev)
err:
dev_err(&qsdev->dev, "probe failed\n");

- channel->cb = NULL;
+ qcom_smd_channel_set_callback(channel, NULL);
kfree(channel->bounce_buffer);
channel->bounce_buffer = NULL;

@@ -851,16 +863,13 @@ static int qcom_smd_dev_remove(struct device *dev)
struct qcom_smd_device *qsdev = to_smd_device(dev);
struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
struct qcom_smd_channel *channel = qsdev->channel;
- unsigned long flags;

qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);

/*
* Make sure we don't race with the code receiving data.
*/
- spin_lock_irqsave(&channel->recv_lock, flags);
- channel->cb = NULL;
- spin_unlock_irqrestore(&channel->recv_lock, flags);
+ qcom_smd_channel_set_callback(channel, NULL);

/* Wake up any sleepers in qcom_smd_send() */
wake_up_interruptible(&channel->fblockread_event);
diff --git a/include/linux/soc/qcom/smd.h b/include/linux/soc/qcom/smd.h
index d0cb6d189a0a..65a64fcdb1aa 100644
--- a/include/linux/soc/qcom/smd.h
+++ b/include/linux/soc/qcom/smd.h
@@ -26,6 +26,8 @@ struct qcom_smd_device {
struct qcom_smd_channel *channel;
};

+typedef int (*qcom_smd_cb_t)(struct qcom_smd_device *, const void *, size_t);
+
/**
* struct qcom_smd_driver - smd driver struct
* @driver: underlying device driver
@@ -42,7 +44,7 @@ struct qcom_smd_driver {

int (*probe)(struct qcom_smd_device *dev);
void (*remove)(struct qcom_smd_device *dev);
- int (*callback)(struct qcom_smd_device *, const void *, size_t);
+ qcom_smd_cb_t callback;
};

int qcom_smd_driver_register(struct qcom_smd_driver *drv);
--
2.4.2

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