[PATCH 10/12] HID: i2c-hid: use helpers to do endian conversion in i2c_hid_get_input()

From: Dmitry Torokhov
Date: Tue Jan 18 2022 - 02:27:58 EST


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@xxxxxxxxx>
---
drivers/hid/i2c-hid/i2c-hid-core.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 433b6692f277..07c2ea057013 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -508,9 +508,9 @@ static int i2c_hid_hwreset(struct i2c_hid *ihid)

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;
}
@@ -555,10 +556,9 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);

if (test_bit(I2C_HID_STARTED, &ihid->flags))
- hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
- ret_size - 2, 1);
-
- return;
+ hid_input_report(ihid->hid, HID_INPUT_REPORT,
+ ihid->inbuf + sizeof(__le16),
+ ret_size - sizeof(__le16), 1);
}

static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
--
2.34.1.703.g22d0c6ccf7-goog