Hi, On Thu, Apr 24, 2014 at 11:42 PM, Felipe Balbi <[email protected]> wrote: > On Thu, Apr 24, 2014 at 09:34:49PM +0900, Chanwoo Choi wrote: >> This patch add APIs to control the extcon device on extcon provider driver. >> The extcon_dev_allocate() allocates the memory of extcon device and >> initializes >> supported cables. And then extcon_dev_free() decrement the reference of the >> device of extcon device and free the memory of the extcon device. This APIs >> must need to implement devm_extcon_dev_allocate()/free() APIs. >> >> Signed-off-by: Chanwoo Choi <[email protected]> >> --- >> drivers/extcon/extcon-class.c | 39 +++++++++++++++++++++++++++++++++++++++ >> include/linux/extcon.h | 13 +++++++++++++ >> 2 files changed, 52 insertions(+) >> >> diff --git a/drivers/extcon/extcon-class.c b/drivers/extcon/extcon-class.c >> index f6df689..bec66d4 100644 >> --- a/drivers/extcon/extcon-class.c >> +++ b/drivers/extcon/extcon-class.c >> @@ -565,6 +565,45 @@ static void dummy_sysfs_dev_release(struct device *dev) >> { >> } >> >> +/* >> + * extcon_dev_allocate() - Allocate the memory of extcon device. >> + * @supported_cable: Array of supported cable names ending with NULL. >> + * If supported_cable is NULL, cable name related APIs >> + * are disabled. >> + * >> + * This function allocates the memory for extcon device without allocating >> + * memory in each extcon provider driver and initialize default setting for >> + * extcon device. >> + * >> + * Return the pointer of extcon device if success or ERR_PTR(err) if fail >> + */ >> +struct extcon_dev *extcon_dev_allocate(const char **supported_cable) >> +{ >> + struct extcon_dev *edev; >> + >> + edev = kzalloc(sizeof(*edev), GFP_KERNEL); >> + if (!edev) { >> + pr_err("Failed to allocate the memory for extcon device\n"); >> + return ERR_PTR(-ENOMEM); >> + } >> + >> + edev->max_supported = 0; >> + edev->supported_cable = supported_cable; >> + >> + return edev; >> +} >> + >> +/* >> + * extcon_dev_free() - Free the memory of extcon device. >> + * @edev: the extcon device to free >> + */ >> +void extcon_dev_free(struct extcon_dev *edev) >> +{ >> + if (edev) >> + kfree(edev); > > kfree(NULL) is safe
I don't understand about meaning 'kfree(NULL)'. Why do I free 'NULL' pointer' instead of 'edev' pointer? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
