Re: [PATCH 2/2] HID: multitouch: devm conversion

[Andy Shevchenko]

On Wed, Jul 24, 2013 at 6:29 PM, Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
> HID special drivers can use safely the devres API.
> Use it to remove 25 lines of code and to clean up a little the error paths.
>
> Besides the pur kzalloc -> devm_kzalloc conversions, I changed the

Typo 'pur' -> 'put'

> place of the allocation of the new name. Doing this right in
> mt_input_configured() removes the kstrdup call which was not very helpful
> and the new way is simpler to understand (and to debug).

Thanks for the patch! I'm sorry I didn't find time to do this by myself.
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> ---
>  drivers/hid/hid-multitouch.c | 71 ++++++++++++++------------------------------
>  1 file changed, 23 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index cb0e361..0fe00e2 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -261,17 +261,6 @@ static struct mt_class mt_classes[] = {
>         { }
>  };
>
> -static void mt_free_input_name(struct hid_input *hi)
> -{
> -       struct hid_device *hdev = hi->report->device;
> -       const char *name = hi->input->name;
> -
> -       if (name != hdev->name) {
> -               hi->input->name = hdev->name;
> -               kfree(name);
> -       }
> -}
> -
>  static ssize_t mt_show_quirks(struct device *dev,
>                            struct device_attribute *attr,
>                            char *buf)
> @@ -415,13 +404,6 @@ static void mt_pen_report(struct hid_device *hid, struct hid_report *report)
>  static void mt_pen_input_configured(struct hid_device *hdev,
>                                         struct hid_input *hi)
>  {
> -       char *name = kzalloc(strlen(hi->input->name) + 5, GFP_KERNEL);
> -       if (name) {
> -               sprintf(name, "%s Pen", hi->input->name);
> -               mt_free_input_name(hi);
> -               hi->input->name = name;
> -       }
> -
>         /* force BTN_STYLUS to allow tablet matching in udev */
>         __set_bit(BTN_STYLUS, hi->input->keybit);
>  }
> @@ -928,16 +910,26 @@ static void mt_post_parse(struct mt_device *td)
>  static void mt_input_configured(struct hid_device *hdev, struct hid_input *hi)
>  {
>         struct mt_device *td = hid_get_drvdata(hdev);
> -       char *name = kstrdup(hdev->name, GFP_KERNEL);
> -
> -       if (name)
> -               hi->input->name = name;
> +       char *name;
> +       const char *suffix = NULL;
>
>         if (hi->report->id == td->mt_report_id)
>                 mt_touch_input_configured(hdev, hi);
>
> -       if (hi->report->id == td->pen_report_id)
> +       if (hi->report->field[0]->physical == HID_DG_STYLUS) {
> +               suffix = "Pen";
>                 mt_pen_input_configured(hdev, hi);
> +       }
> +
> +       if (suffix) {
> +               name = devm_kzalloc(&hi->input->dev,
> +                                   strlen(hdev->name) + strlen(suffix) + 2,
> +                                   GFP_KERNEL);
> +               if (name) {
> +                       sprintf(name, "%s %s", hdev->name, suffix);
> +                       hi->input->name = name;
> +               }
> +       }
>  }
>
>  static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
> @@ -945,7 +937,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         int ret, i;
>         struct mt_device *td;
>         struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
> -       struct hid_input *hi;
>
>         for (i = 0; mt_classes[i].name ; i++) {
>                 if (id->driver_data == mt_classes[i].name) {
> @@ -967,7 +958,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         hdev->quirks |= HID_QUIRK_MULTI_INPUT;
>         hdev->quirks |= HID_QUIRK_NO_EMPTY_INPUT;
>
> -       td = kzalloc(sizeof(struct mt_device), GFP_KERNEL);
> +       td = devm_kzalloc(&hdev->dev, sizeof(struct mt_device), GFP_KERNEL);
>         if (!td) {
>                 dev_err(&hdev->dev, "cannot allocate multitouch data\n");
>                 return -ENOMEM;
> @@ -980,11 +971,11 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>         td->pen_report_id = -1;
>         hid_set_drvdata(hdev, td);
>
> -       td->fields = kzalloc(sizeof(struct mt_fields), GFP_KERNEL);
> +       td->fields = devm_kzalloc(&hdev->dev, sizeof(struct mt_fields),
> +                                 GFP_KERNEL);
>         if (!td->fields) {
>                 dev_err(&hdev->dev, "cannot allocate multitouch fields data\n");
> -               ret = -ENOMEM;
> -               goto fail;
> +               return -ENOMEM;
>         }
>
>         if (id->vendor == HID_ANY_ID && id->product == HID_ANY_ID)
> @@ -992,29 +983,22 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
>
>         ret = hid_parse(hdev);
>         if (ret != 0)
> -               goto fail;
> +               return ret;
>
>         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
>         if (ret)
> -               goto hid_fail;
> +               return ret;
>
>         ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
>
>         mt_set_maxcontacts(hdev);
>         mt_set_input_mode(hdev);
>
> -       kfree(td->fields);
> +       /* release .fields memory as it is not used anymore */
> +       devm_kfree(&hdev->dev, td->fields);
>         td->fields = NULL;
>
>         return 0;
> -
> -hid_fail:
> -       list_for_each_entry(hi, &hdev->inputs, list)
> -               mt_free_input_name(hi);
> -fail:
> -       kfree(td->fields);
> -       kfree(td);
> -       return ret;
>  }
>
>  #ifdef CONFIG_PM
> @@ -1039,17 +1023,8 @@ static int mt_resume(struct hid_device *hdev)
>
>  static void mt_remove(struct hid_device *hdev)
>  {
> -       struct mt_device *td = hid_get_drvdata(hdev);
> -       struct hid_input *hi;
> -
>         sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);
> -       list_for_each_entry(hi, &hdev->inputs, list)
> -               mt_free_input_name(hi);
> -
>         hid_hw_stop(hdev);
> -
> -       kfree(td);
> -       hid_set_drvdata(hdev, NULL);
>  }
>
>  static const struct hid_device_id mt_devices[] = {
> --
> 1.8.3.1
>



--
With Best Regards,
Andy Shevchenko
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