Re: [PATCH 10/14] HID: i2c-hid: reorder allocation/free of buffers

From: Benjamin Tissoires
Date: Wed Dec 05 2012 - 05:12:34 EST


On Wed, Dec 5, 2012 at 11:10 AM, Jean Delvare <khali@xxxxxxxxxxxx> wrote:
> On Tue, 4 Dec 2012 16:27:51 +0100, 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@xxxxxxxxx>
>> ---
>> 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 dcacfc4..4e3f80b 100644
>> --- a/drivers/hid/i2c-hid/i2c-hid.c
>> +++ b/drivers/hid/i2c-hid/i2c-hid.c
>> @@ -465,48 +465,38 @@ 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,
>> @@ -611,22 +601,19 @@ 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))
>> @@ -844,8 +831,9 @@ 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)
>
> Yes, looks much better.
>
> Reviewed-by: Jean Delvare <khali@xxxxxxxxxxxx>

Thanks Jean,

as mentioned in 2/14, this patch need the fix in 2/14 to be able to
work. Jiri, I'll try to send a v2 ASAP so that you can pick both in
the right order (otherwise, the bisect may fall between the two).

Cheers,
Benjamin

>
> --
> Jean Delvare
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