[PATCH 4/5] staging: fsl-mc: add counter to track number of root DPRCs

From: itai.katz
Date: Sun Oct 04 2015 - 03:10:58 EST


From: Itai Katz <itai.katz@xxxxxxxxxxxxx>

Add a counter to track the number of root DPRCs.
When this counter is greater then 0 it means that at least
one root DPRC device exists.

Signed-off-by: Itai Katz <itai.katz@xxxxxxxxxxxxx>
---
drivers/staging/fsl-mc/bus/mc-bus.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/fsl-mc/bus/mc-bus.c b/drivers/staging/fsl-mc/bus/mc-bus.c
index 37f51f3..8a2b99c 100644
--- a/drivers/staging/fsl-mc/bus/mc-bus.c
+++ b/drivers/staging/fsl-mc/bus/mc-bus.c
@@ -109,6 +109,8 @@ struct bus_type fsl_mc_bus_type = {
};
EXPORT_SYMBOL_GPL(fsl_mc_bus_type);

+static atomic_t root_dprc_count = ATOMIC_INIT(0);
+
static int fsl_mc_driver_probe(struct device *dev)
{
struct fsl_mc_driver *mc_drv;
@@ -213,7 +215,7 @@ EXPORT_SYMBOL_GPL(fsl_mc_driver_unregister);
*/
bool fsl_mc_bus_exists(void)
{
- return fsl_mc_bus_type.dev_root;
+ return atomic_read(&root_dprc_count) > 0;
}
EXPORT_SYMBOL_GPL(fsl_mc_bus_exists);

@@ -458,6 +460,8 @@ int fsl_mc_device_add(struct dprc_obj_desc *obj_desc,

if (!fsl_mc_bus_exists())
fsl_mc_bus_type.dev_root = &mc_dev->dev;
+
+ atomic_inc(&root_dprc_count);
}

error = get_dprc_icid(mc_io2, obj_desc->id, &mc_dev->icid);
@@ -540,8 +544,13 @@ void fsl_mc_device_remove(struct fsl_mc_device *mc_dev)
mc_dev->mc_io = NULL;
}

- if (fsl_mc_is_root_dprc(&mc_dev->dev))
+ if (fsl_mc_is_root_dprc(&mc_dev->dev)) {
fsl_mc_bus_type.dev_root = NULL;
+ if (atomic_read(&root_dprc_count) > 0)
+ atomic_dec(&root_dprc_count);
+ else
+ WARN_ON(1);
+ }
}

if (mc_bus)
--
1.7.9.5

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