1 files changed, 13 insertions, 32 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index b50860db92f1..21aafc8f48c8 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -807,34 +807,18 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
         unsigned int dsize;
         int ret;
 
-        /* Fetch the length of HID description, retrieve the 4 first bytes:
-         * bytes 0-1 -> length
-         * bytes 2-3 -> bcdVersion (has to be 1.00) */
-        ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer, 4);
-
-        i2c_hid_dbg(ihid, "%s, ihid->hdesc_buffer: %4ph\n", __func__,
-                        ihid->hdesc_buffer);
-
+        /* i2c hid fetch using a fixed descriptor size (30 bytes) */
+        i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
+        ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
+                                sizeof(struct i2c_hid_desc));
         if (ret) {
-                dev_err(&client->dev,
-                        "unable to fetch the size of HID descriptor (ret=%d)\n",
-                        ret);
-                return -ENODEV;
-        }
-
-        dsize = le16_to_cpu(hdesc->wHIDDescLength);
-        /*
-         * the size of the HID descriptor should at least contain
-         * its size and the bcdVersion (4 bytes), and should not be greater
-         * than sizeof(struct i2c_hid_desc) as we directly fill this struct
-         * through i2c_hid_command.
-         */
-        if (dsize < 4 || dsize > sizeof(struct i2c_hid_desc)) {
-                dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
-                        dsize);
+                dev_err(&client->dev, "hid_descr_cmd failed\n");
                 return -ENODEV;
         }
 
+        /* Validate the length of HID descriptor, the 4 first bytes:
+         * bytes 0-1 -> length
+         * bytes 2-3 -> bcdVersion (has to be 1.00) */
         /* check bcdVersion == 1.0 */
         if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
                 dev_err(&client->dev,
@@ -843,17 +827,14 @@ static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
                 return -ENODEV;
         }
 
-        i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
-
-        ret = i2c_hid_command(client, &hid_descr_cmd, ihid->hdesc_buffer,
-                                dsize);
-        if (ret) {
-                dev_err(&client->dev, "hid_descr_cmd Fail\n");
+        /* Descriptor length should be 30 bytes as per the specification */
+        dsize = le16_to_cpu(hdesc->wHIDDescLength);
+        if (dsize != sizeof(struct i2c_hid_desc)) {
+                dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
+                        dsize);
                 return -ENODEV;
         }
-
         i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
-
         return 0;
 }