From a394d635193b641f2c86ead5ada5b115d57c51f8 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sun, 6 Sep 2015 01:46:54 +0300 Subject: 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 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 Signed-off-by: Alexey Klimov Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index cf8b91b23a76..9ce2f156d382 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1437,8 +1437,7 @@ 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) { -- cgit v1.2.3