HID: i2c-hid: use helpers to do endian conversion in i2c_hid_get_input()

It is better to use helpers to do endian conversion as it documents
and draws attention to it, and might be a bit more performant as
well.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 67c80bf..a32502d 100644 (file)
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -508,9 +508,9 @@ out_unlock:
 
 static void i2c_hid_get_input(struct i2c_hid *ihid)
 {
+       u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
+       u16 ret_size;
        int ret;
-       u32 ret_size;
-       int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
 
        if (size > ihid->bufsize)
                size = ihid->bufsize;
@@ -525,8 +525,8 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
                return;
        }
 
-       ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
-
+       /* Receiving buffer is properly aligned */
+       ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
        if (!ret_size) {
                /* host or device initiated RESET completed */
                if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
@@ -534,19 +534,20 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
                return;
        }
 
-       if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
-               dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
-                             "there's no data\n", __func__);
+       if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
+               dev_warn_once(&ihid->client->dev,
+                             "%s: IRQ triggered but there's no data\n",
+                             __func__);
                return;
        }
 
-       if ((ret_size > size) || (ret_size < 2)) {
+       if (ret_size > size || ret_size < sizeof(__le16)) {
                if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
-                       ihid->inbuf[0] = size & 0xff;
-                       ihid->inbuf[1] = size >> 8;
+                       *(__le16 *)ihid->inbuf = cpu_to_le16(size);
                        ret_size = size;
                } else {
-                       dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
+                       dev_err(&ihid->client->dev,
+                               "%s: incomplete report (%d/%d)\n",
                                __func__, size, ret_size);
                        return;
                }
@@ -557,8 +558,9 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
        if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
                pm_wakeup_event(&ihid->client->dev, 0);
 
-               hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
-                               ret_size - 2, 1);
+               hid_input_report(ihid->hid, HID_INPUT_REPORT,
+                               ihid->inbuf + sizeof(__le16),
+                               ret_size - sizeof(__le16), 1);
        }
 
        return;