diff options
| author | Guenter Roeck <linux@roeck-us.net> | 2015-09-06 01:46:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-10-22 14:37:50 -0700 |
| commit | 69e686057711bf17907ba68e19ceffdfca80d788 (patch) | |
| tree | d1d775d71cc0039bef1f69e6a87ed90d51b8c82e | |
| parent | 919845cb331e066a042a8060e84bb9dc6ba390bf (diff) | |
spi: Fix documentation of spi_alloc_master()
commit a394d635193b641f2c86ead5ada5b115d57c51f8 upstream.
Actually, spi_master_put() after spi_alloc_master() must _not_ be followed
by kfree(). The memory is already freed with the call to spi_master_put()
through spi_master_class, which registers a release function. Calling both
spi_master_put() and kfree() results in often nasty (and delayed) crashes
elsewhere in the kernel, often in the networking stack.
This reverts commit eb4af0f5349235df2e4a5057a72fc8962d00308a.
Link to patch and concerns: https://lkml.org/lkml/2012/9/3/269
or
http://lkml.iu.edu/hypermail/linux/kernel/1209.0/00790.html
Alexey Klimov: This revert becomes valid after
94c69f765f1b4a658d96905ec59928e3e3e07e6a when spi-imx.c
has been fixed and there is no need to call kfree() so comment
for spi_alloc_master() should be fixed.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/spi/spi.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 32b7bb111eb6..7c159634aaae 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1030,8 +1030,7 @@ static struct class spi_master_class = { * * The caller is responsible for assigning the bus number and initializing * the master's methods before calling spi_register_master(); and (after errors - * adding the device) calling spi_master_put() and kfree() to prevent a memory - * leak. + * adding the device) calling spi_master_put() to prevent a memory leak. */ struct spi_master *spi_alloc_master(struct device *dev, unsigned size) { |