Commit a394d635 authored by Guenter Roeck's avatar Guenter Roeck Committed by Mark Brown

spi: Fix documentation of spi_alloc_master()

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 eb4af0f5.

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
94c69f76 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: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
parent d770e558
...@@ -1437,8 +1437,7 @@ static struct class spi_master_class = { ...@@ -1437,8 +1437,7 @@ static struct class spi_master_class = {
* *
* The caller is responsible for assigning the bus number and initializing * The caller is responsible for assigning the bus number and initializing
* the master's methods before calling spi_register_master(); and (after errors * 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 * adding the device) calling spi_master_put() to prevent a memory leak.
* leak.
*/ */
struct spi_master *spi_alloc_master(struct device *dev, unsigned size) struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
{ {
......
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