Re: [PATCH] Input: davinci_keyscan: Free memory occupied by davinci key scan device

[arvindY]

On Tuesday 14 November 2017 11:44 PM, Dmitry Torokhov wrote:

On Tue, Nov 14, 2017 at 07:15:14PM +0530, Arvind Yadav wrote:

Here, key_dev is NULL in input_free_device() and It will not free
memory occupied by davinci key scan device. Move "key_dev = NULL"
after input_free_device().

No, this is absolutely wrong. It is disallowed to call
input_free_device() after calling input_unregister_device(), because
input core will free the device once the last reference is dropped. That
is why we set "key_dev" to NULL to turn input_free_device() into a noop.

Yes, You are correct. Once device is unregistered it will get freed.

Thanks, :)

Signed-off-by: Arvind Yadav <arvind.yadav...@gmail.com>
---
  drivers/input/keyboard/davinci_keyscan.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/keyboard/davinci_keyscan.c 
b/drivers/input/keyboard/davinci_keyscan.c
index b20a5d0..22cb8d2 100644
--- a/drivers/input/keyboard/davinci_keyscan.c
+++ b/drivers/input/keyboard/davinci_keyscan.c
@@ -290,13 +290,13 @@ static int __init davinci_ks_probe(struct platform_device 
*pdev)
        free_irq(davinci_ks->irq, davinci_ks);
  fail5:
        input_unregister_device(davinci_ks->input);
-       key_dev = NULL;
  fail4:
        iounmap(davinci_ks->base);
  fail3:
        release_mem_region(davinci_ks->pbase, davinci_ks->base_size);
  fail2:
        input_free_device(key_dev);
+       key_dev = NULL;
  fail1:
        kfree(davinci_ks);

--

1.9.1

Thanks.