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.
---
drivers/hid/hid-huion.c | 96 +++++++++++++++++++++++++------------------------
1 file changed, 49 insertions(+), 47 deletions(-)
diff --git a/drivers/hid/hid-huion.c b/drivers/hid/hid-huion.c
index 60f44cd..a683d4b 100644
--- a/drivers/hid/hid-huion.c
+++ b/drivers/hid/hid-huion.c
@@ -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;
- } 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;
- }
+ /* 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);
+ /* 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++;
- }
+ /* 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++;
}
}
--
2.0.1
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