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From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Jiri Kosina <jikos@kernel.org>,
	Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Angela Czubak <acz@semihalf.com>,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 10/12] HID: i2c-hid: use helpers to do endian conversion in i2c_hid_get_input()
Date: Mon, 17 Jan 2022 23:26:26 -0800	[thread overview]
Message-ID: <20220118072628.1617172-11-dmitry.torokhov@gmail.com> (raw)
In-Reply-To: <20220118072628.1617172-1-dmitry.torokhov@gmail.com>

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>
---
 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


  parent reply	other threads:[~2022-01-18  7:27 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-18  7:26 [PATCH 00/12] i2c-hid: fixes for unnumbered reports and other improvements Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 01/12] HID: i2c-hid: fix handling numbered reports with IDs of 15 and above Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 02/12] HID: i2c-hid: fix GET/SET_REPORT for unnumbered reports Dmitry Torokhov
2022-02-03 14:16   ` Benjamin Tissoires
2022-01-18  7:26 ` [PATCH 03/12] HID: i2c-hid: use "struct i2c_hid" as argument in most calls Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 04/12] HID: i2c-hid: refactor reset command Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 05/12] HID: i2c-hid: explicitly code setting and sending reports Dmitry Torokhov
2022-01-19 15:31   ` Angela Czubak
2022-01-20  6:27     ` Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 06/12] HID: i2c-hid: define i2c_hid_read_register() and use it Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 07/12] HID: i2c-hid: create a helper for SET_POWER command Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 08/12] HID: i2c-hid: convert i2c_hid_execute_reset() to use i2c_hid_xfer() Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 09/12] HID: i2c-hid: rework i2c_hid_get_report() " Dmitry Torokhov
2022-01-18  7:26 ` Dmitry Torokhov [this message]
2022-01-18  7:26 ` [PATCH 11/12] HID: i2c-hid: no longer need raw access to HID descriptor structure Dmitry Torokhov
2022-01-18  7:26 ` [PATCH 12/12] HID: i2c-hid: note that I2C xfer buffers are DMA-safe Dmitry Torokhov
2022-02-02 13:56 ` [PATCH 00/12] i2c-hid: fixes for unnumbered reports and other improvements Jiri Kosina
2022-02-02 17:59   ` Benjamin Tissoires
2022-02-03 14:22     ` Benjamin Tissoires
2022-02-14  9:46       ` Jiri Kosina

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