[PATCH v2 2/4] HID: i2c-hid: reorder allocation/free of buffers

Benjamin Tissoires
2012-12-05T14:02:54Z

Simplifies i2c_hid_alloc_buffers tests, and makes this function
responsible of the assignment of ihid->bufsize.
The condition for the reallocation in i2c_hid_start is then simpler.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
---
drivers/hid/i2c-hid/i2c-hid.c | 68 ++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 40 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index 34cca42..d00f185 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -464,48 +464,38 @@ static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
}
}

-static int i2c_hid_alloc_buffers(struct i2c_hid *ihid)
+static void i2c_hid_free_buffers(struct i2c_hid *ihid)
+{
+ kfree(ihid->inbuf);
+ kfree(ihid->argsbuf);
+ kfree(ihid->cmdbuf);
+ ihid->inbuf = NULL;
+ ihid->cmdbuf = NULL;
+ ihid->argsbuf = NULL;
+ ihid->bufsize = 0;
+}
+
+static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
{
/* the worst case is computed from the set_report command with a
* reportID > 15 and the maximum report length */
int args_len = sizeof(__u8) + /* optional ReportID byte */
sizeof(__u16) + /* data register */
sizeof(__u16) + /* size of the report */
- ihid->bufsize; /* report */
-
- ihid->inbuf = kzalloc(ihid->bufsize, GFP_KERNEL);
-
- if (!ihid->inbuf)
- return -ENOMEM;
+ report_size; /* report */

+ ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
-
- if (!ihid->argsbuf) {
- kfree(ihid->inbuf);
- return -ENOMEM;
- }
-
ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);

- if (!ihid->cmdbuf) {
- kfree(ihid->inbuf);
- kfree(ihid->argsbuf);
- ihid->inbuf = NULL;
- ihid->argsbuf = NULL;
+ if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
+ i2c_hid_free_buffers(ihid);
return -ENOMEM;
}

- return 0;
-}
+ ihid->bufsize = report_size;

-static void i2c_hid_free_buffers(struct i2c_hid *ihid)
-{
- kfree(ihid->inbuf);
- kfree(ihid->argsbuf);
- kfree(ihid->cmdbuf);
- ihid->inbuf = NULL;
- ihid->cmdbuf = NULL;
- ihid->argsbuf = NULL;
+ return 0;
}

static int i2c_hid_get_raw_report(struct hid_device *hid,
@@ -610,22 +600,19 @@ static int i2c_hid_start(struct hid_device *hid)
struct i2c_client *client = hid->driver_data;
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret;
- int old_bufsize = ihid->bufsize;
+ unsigned int bufsize = HID_MIN_BUFFER_SIZE;

- ihid->bufsize = HID_MIN_BUFFER_SIZE;
- i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &ihid->bufsize);
- i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &ihid->bufsize);
- i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &ihid->bufsize);
+ i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
+ i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
+ i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);

- if (ihid->bufsize > old_bufsize || !ihid->inbuf || !ihid->cmdbuf) {
+ if (bufsize > ihid->bufsize) {
i2c_hid_free_buffers(ihid);

- ret = i2c_hid_alloc_buffers(ihid);
+ ret = i2c_hid_alloc_buffers(ihid, bufsize);

- if (ret) {
- ihid->bufsize = old_bufsize;
+ if (ret)
return ret;
- }
}

if (!(hid->quirks & HID_QUIRK_NO_INIT_REPORTS))
@@ -849,8 +836,9 @@ static int __devinit i2c_hid_probe(struct i2c_client *client,
/* we need to allocate the command buffer without knowing the maximum
* size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
* real computation later. */
- ihid->bufsize = HID_MIN_BUFFER_SIZE;
- i2c_hid_alloc_buffers(ihid);
+ ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
+ if (ret < 0)
+ goto err;

ret = i2c_hid_fetch_hid_descriptor(ihid);
if (ret < 0)
--
1.8.0.1