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

Jiri Kosina
2012-12-06T09:56:05Z

On Wed, 5 Dec 2012, Benjamin Tissoires wrote:

> 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-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Reviewed-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.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)

Applied, thank you.

--
Jiri Kosina
SUSE Labs