Re: [PATCH 2/3] HID: Implement Wacom quirk in the kernel

Jiri Kosina
2010-02-03T14:50:32Z

On Fri, 29 Jan 2010, Ping Cheng wrote:

> +       rep_data[0] = 0x03; rep_data[1] = 0x00;
> +       limit =3;
> +       do {
> +               ret = hdev->hid_output_raw_report(hdev, rep_data, 2,
> +                               HID_FEATURE_REPORT);
> +       } while (ret < 0 && limit-- > 0);
>
>
> hdev->hid_output_raw_report error is not a hard failure, i.e., the following four lines are unnecessay. We can continue with the
> rest of the code.
>
> +       if (ret < 0) {
> +               dev_err(&hdev->dev, "failed to poke device #1, %d\n", ret);
> +               goto err_free;
> +       }
> +
> +       /* 0x06 - high reporting speed, 0x05 - low speed */
> +       rep_data[0] = 0x06; rep_data[1] = 0x00;
> +       limit = 3;
> +       do {
> +               ret = hdev->hid_output_raw_report(hdev, rep_data, 2,
> +                               HID_FEATURE_REPORT);
> +       } while (ret < 0 && limit-- > 0);
>
>
> Same comments apply here. "/* Note that if query fails it is not a hard failure */" is the comments we use in the corresponding
> Wacom USB driver, wacom_sys.c

Thanks for the feedback. I have queued the patch below on top of all the
other changes.

From: Jiri Kosina <jkosina@suse.cz>
Subject: [PATCH] HID: make Wacom modesetting failures non-fatal

With Wacom tablet mode-setting moved from userspace into kernel,
we don't have to consider failures of device queries through the
_raw callback as hard failure, as the driver can safely continue
anyway.

This is consistent with the current USB driver in wacom_sys.c

Reported-by: Ping Cheng <pinglinux@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
---
drivers/hid/hid-wacom.c | 17 +++++++++--------
1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/hid/hid-wacom.c b/drivers/hid/hid-wacom.c
index b8778db..8d3b46f 100644
--- a/drivers/hid/hid-wacom.c
+++ b/drivers/hid/hid-wacom.c
@@ -181,6 +181,11 @@ static int wacom_probe(struct hid_device *hdev,
goto err_free;
}

+ /*
+ * Note that if the raw queries fail, it's not a hard failure and it
+ * is safe to continue
+ */
+
/* Set Wacom mode2 */
rep_data[0] = 0x03; rep_data[1] = 0x00;
limit = 3;
@@ -188,10 +193,8 @@ static int wacom_probe(struct hid_device *hdev,
ret = hdev->hid_output_raw_report(hdev, rep_data, 2,
HID_FEATURE_REPORT);
} while (ret < 0 && limit-- > 0);
- if (ret < 0) {
- dev_err(&hdev->dev, "failed to poke device #1, %d\n", ret);
- goto err_free;
- }
+ if (ret < 0)
+ dev_warn(&hdev->dev, "failed to poke device #1, %d\n", ret);

/* 0x06 - high reporting speed, 0x05 - low speed */
rep_data[0] = 0x06; rep_data[1] = 0x00;
@@ -200,10 +203,8 @@ static int wacom_probe(struct hid_device *hdev,
ret = hdev->hid_output_raw_report(hdev, rep_data, 2,
HID_FEATURE_REPORT);
} while (ret < 0 && limit-- > 0);
- if (ret < 0) {
- dev_err(&hdev->dev, "failed to poke device #2, %d\n", ret);
- goto err_free;
- }
+ if (ret < 0)
+ dev_warn(&hdev->dev, "failed to poke device #2, %d\n", ret);

hidinput = list_entry(hdev->inputs.next, struct hid_input, list);
input = hidinput->input;
--
1.6.4.2