linux-kernel - [PATCH 2/4] HID: alps: Save a memory allocation in 't4_read_write

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Date:   Mon, 19 Mar 2018 21:53:27 +0100
From:   Christophe JAILLET <christophe.jaillet@...adoo.fr>
To:     masaki.ota@...alps.com, jikos@...nel.org,
        benjamin.tissoires@...hat.com
Cc:     linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>
Subject: [PATCH 2/4] HID: alps: Save a memory allocation in 't4_read_write_register()' when writing data

if 'read_flag' is false, there is no need to allocate and free memory.
We can simply avoid the memory allocation and pass NULL to kfree.

Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
---
 drivers/hid/hid-alps.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-alps.c b/drivers/hid/hid-alps.c
index 925396fdf0d9..fe8a0624d5e4 100644
--- a/drivers/hid/hid-alps.c
+++ b/drivers/hid/hid-alps.c
@@ -171,7 +171,7 @@ static int t4_read_write_register(struct hid_device *hdev, u32 address,
 	int ret;
 	u16 check_sum;
 	u8 *input;
-	u8 *readbuf;
+	u8 *readbuf = NULL;
 
 	input = kzalloc(T4_FEATURE_REPORT_LEN, GFP_KERNEL);
 	if (!input)
@@ -204,8 +204,8 @@ static int t4_read_write_register(struct hid_device *hdev, u32 address,
 		goto exit;
 	}
 
-	readbuf = kzalloc(T4_FEATURE_REPORT_LEN, GFP_KERNEL);
 	if (read_flag) {
+		readbuf = kzalloc(T4_FEATURE_REPORT_LEN, GFP_KERNEL);
 		if (!readbuf) {
 			ret = -ENOMEM;
 			goto exit;
-- 
2.14.1