The call sequence spi_alloc_master/spi_register_master/spi_unregister_master is
complete; it reduces the device reference count to zero, which results in
device memory being freed. An extra call to spi_master_put is unnecessary
and results in an access to free memory.
At the same time, since the call to spi_unregister_master results in device
memory being freed, it must no longer be accessed afterwards.
To fix both problems, call spi_master_get to get an extra reference to the
device, and call spi_master_put only after the last access to device data.
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
drivers/spi/spi-mpc52xx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/spi-mpc52xx.c b/drivers/spi/spi-mpc52xx.c
index a749589..0454106 100644
--- a/drivers/spi/spi-mpc52xx.c
+++ b/drivers/spi/spi-mpc52xx.c
@@ -529,7 +529,7 @@ static int __devinit mpc52xx_spi_probe(struct
platform_device *op)
static int __devexit mpc52xx_spi_remove(struct platform_device *op)
{
- struct spi_master *master = dev_get_drvdata(&op->dev);
+ struct spi_master *master = spi_master_get(dev_get_drvdata(&op->dev));
struct mpc52xx_spi *ms = spi_master_get_devdata(master);
int i;
@@ -541,8 +541,8 @@ static int __devexit mpc52xx_spi_remove(struct
platform_device *op)
kfree(ms->gpio_cs);
spi_unregister_master(master);
- spi_master_put(master);
iounmap(ms->regs);
+ spi_master_put(master);
return 0;
}
--
1.7.9.7
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