* [PATCH V1] hid: hid-multitouch:- No need of devm functions
@ 2016-12-07 14:59 Arvind Yadav
2016-12-13 8:24 ` Benjamin Tissoires
0 siblings, 1 reply; 2+ messages in thread
From: Arvind Yadav @ 2016-12-07 14:59 UTC (permalink / raw)
To: jikos, benjamin.tissoires; +Cc: linux-input, linux-kernel
In function mt_probe, the memory allocated for td->fields
is live within the function only. After the allocation
it is immediately freed with devm_kfree. There is no need
to allocate memory for td->fields with devm function so
replace devm_kzalloc with kzalloc and devm_kfree with kfree.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
---
drivers/hid/hid-multitouch.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index fb6f1f4..13ea309 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -1126,11 +1126,11 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
td->mt_report_id = -1;
hid_set_drvdata(hdev, td);
- td->fields = devm_kzalloc(&hdev->dev, sizeof(struct mt_fields),
- GFP_KERNEL);
+ td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);
if (!td->fields) {
dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto error_nomem;
}
if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
@@ -1138,11 +1138,11 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = hid_parse(hdev);
if (ret != 0)
- return ret;
+ goto error_free;
ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
if (ret)
- return ret;
+ goto error_free;
ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
if (ret)
@@ -1153,10 +1153,15 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
mt_set_input_mode(hdev);
/* release .fields memory as it is not used anymore */
- devm_kfree(&hdev->dev, td->fields);
+ kfree(td->fields);
td->fields = NULL;
return 0;
+
+error_free:
+ kfree(td->fields);
+error_nomem:
+ return ret;
}
#ifdef CONFIG_PM
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V1] hid: hid-multitouch:- No need of devm functions
2016-12-07 14:59 [PATCH V1] hid: hid-multitouch:- No need of devm functions Arvind Yadav
@ 2016-12-13 8:24 ` Benjamin Tissoires
0 siblings, 0 replies; 2+ messages in thread
From: Benjamin Tissoires @ 2016-12-13 8:24 UTC (permalink / raw)
To: Arvind Yadav; +Cc: jikos, linux-input, linux-kernel
On Dec 07 2016 or thereabouts, Arvind Yadav wrote:
> In function mt_probe, the memory allocated for td->fields
> is live within the function only. After the allocation
> it is immediately freed with devm_kfree. There is no need
> to allocate memory for td->fields with devm function so
> replace devm_kzalloc with kzalloc and devm_kfree with kfree.
>
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
> ---
Please don't.
It's true that the buffer is only used temporary, but there are 2
reasons for that:
- the driver uses devm everywhere
- the return path is simplified by using devm
And here, the error code path will be more complex for no gain.
Cheers,
Benjamin
> drivers/hid/hid-multitouch.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index fb6f1f4..13ea309 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -1126,11 +1126,11 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> td->mt_report_id = -1;
> hid_set_drvdata(hdev, td);
>
> - td->fields = devm_kzalloc(&hdev->dev, sizeof(struct mt_fields),
> - GFP_KERNEL);
> + td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);
> if (!td->fields) {
> dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");
> - return -ENOMEM;
> + ret = -ENOMEM;
> + goto error_nomem;
> }
>
> if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
> @@ -1138,11 +1138,11 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>
> ret = hid_parse(hdev);
> if (ret != 0)
> - return ret;
> + goto error_free;
>
> ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> if (ret)
> - return ret;
> + goto error_free;
>
> ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
> if (ret)
> @@ -1153,10 +1153,15 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> mt_set_input_mode(hdev);
>
> /* release .fields memory as it is not used anymore */
> - devm_kfree(&hdev->dev, td->fields);
> + kfree(td->fields);
> td->fields = NULL;
>
> return 0;
> +
> +error_free:
> + kfree(td->fields);
> +error_nomem:
> + return ret;
> }
>
> #ifdef CONFIG_PM
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-12-13 8:25 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-12-07 14:59 [PATCH V1] hid: hid-multitouch:- No need of devm functions Arvind Yadav
2016-12-13 8:24 ` Benjamin Tissoires
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).