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HID: huion: Fail on parameter retrieval errors 

Fail Huion tablet interface enabling and probing, if parameter retrieval
fails. Move the main code path out of the else block accordingly.

This should prevent devices appearing in a half-working state due to
original report descriptor being used, simplifying diagnostics. This
also makes it easier to add cleanup in later commits, as error handling
is simplified.

Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Nikolai Kondrashov 2014-08-11 20:45:31 +03:00 committed by Jiri Kosina
parent 172bfe09dc
commit 657d6dc419
1 changed files with 50 additions and 48 deletions
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98
drivers/hid/hid-huion.c
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@ -116,6 +116,10 @@ static int huion_tablet_enable(struct hid_device *hdev)
struct usb_device *usb_dev = hid_to_usb_dev(hdev);
struct huion_drvdata *drvdata = hid_get_drvdata(hdev);
__le16 buf[6];
s32 params[HUION_PH_ID_NUM];
s32 resolution;
__u8 *p;
s32 v;
/*
* Read string descriptor containing tablet parameters. The specific
@ -128,56 +132,54 @@ static int huion_tablet_enable(struct hid_device *hdev)
(USB_DT_STRING << 8) + 0x64,
0x0409, buf, sizeof(buf),
USB_CTRL_GET_TIMEOUT);
if (rc == -EPIPE)
hid_warn(hdev, "device parameters not found\n");
else if (rc < 0)
hid_warn(hdev, "failed to get device parameters: %d\n", rc);
else if (rc != sizeof(buf))
hid_warn(hdev, "invalid device parameters\n");
else {
s32 params[HUION_PH_ID_NUM];
s32 resolution;
__u8 *p;
s32 v;
if (rc == -EPIPE) {
hid_err(hdev, "device parameters not found\n");
return -ENODEV;
} else if (rc < 0) {
hid_err(hdev, "failed to get device parameters: %d\n", rc);
return -ENODEV;
} else if (rc != sizeof(buf)) {
hid_err(hdev, "invalid device parameters\n");
return -ENODEV;
}
/* Extract device parameters */
params[HUION_PH_ID_X_LM] = le16_to_cpu(buf[1]);
params[HUION_PH_ID_Y_LM] = le16_to_cpu(buf[2]);
params[HUION_PH_ID_PRESSURE_LM] = le16_to_cpu(buf[4]);
resolution = le16_to_cpu(buf[5]);
if (resolution == 0) {
params[HUION_PH_ID_X_PM] = 0;
params[HUION_PH_ID_Y_PM] = 0;
/* Extract device parameters */
params[HUION_PH_ID_X_LM] = le16_to_cpu(buf[1]);
params[HUION_PH_ID_Y_LM] = le16_to_cpu(buf[2]);
params[HUION_PH_ID_PRESSURE_LM] = le16_to_cpu(buf[4]);
resolution = le16_to_cpu(buf[5]);
if (resolution == 0) {
params[HUION_PH_ID_X_PM] = 0;
params[HUION_PH_ID_Y_PM] = 0;
} else {
params[HUION_PH_ID_X_PM] = params[HUION_PH_ID_X_LM] *
1000 / resolution;
params[HUION_PH_ID_Y_PM] = params[HUION_PH_ID_Y_LM] *
1000 / resolution;
}
/* Allocate fixed report descriptor */
drvdata->rdesc = devm_kmalloc(&hdev->dev,
sizeof(huion_tablet_rdesc_template),
GFP_KERNEL);
if (drvdata->rdesc == NULL) {
hid_err(hdev, "failed to allocate fixed rdesc\n");
return -ENOMEM;
}
drvdata->rsize = sizeof(huion_tablet_rdesc_template);
/* Format fixed report descriptor */
memcpy(drvdata->rdesc, huion_tablet_rdesc_template,
drvdata->rsize);
for (p = drvdata->rdesc;
p <= drvdata->rdesc + drvdata->rsize - 4;) {
if (p[0] == 0xFE && p[1] == 0xED && p[2] == 0x1D &&
p[3] < sizeof(params)) {
v = params[p[3]];
put_unaligned(cpu_to_le32(v), (s32 *)p);
p += 4;
} else {
params[HUION_PH_ID_X_PM] = params[HUION_PH_ID_X_LM] *
1000 / resolution;
params[HUION_PH_ID_Y_PM] = params[HUION_PH_ID_Y_LM] *
1000 / resolution;
}
/* Allocate fixed report descriptor */
drvdata->rdesc = devm_kmalloc(&hdev->dev,
sizeof(huion_tablet_rdesc_template),
GFP_KERNEL);
if (drvdata->rdesc == NULL) {
hid_err(hdev, "failed to allocate fixed rdesc\n");
return -ENOMEM;
}
drvdata->rsize = sizeof(huion_tablet_rdesc_template);
/* Format fixed report descriptor */
memcpy(drvdata->rdesc, huion_tablet_rdesc_template,
drvdata->rsize);
for (p = drvdata->rdesc;
p <= drvdata->rdesc + drvdata->rsize - 4;) {
if (p[0] == 0xFE && p[1] == 0xED && p[2] == 0x1D &&
p[3] < sizeof(params)) {
v = params[p[3]];
put_unaligned(cpu_to_le32(v), (s32 *)p);
p += 4;
} else {
p++;
}
p++;
}
}