linux-kernel - [PATCH v2] HID: i2c-hid: Add I2C_HID_QUIRK_NO_DELAY_AFTER_PWR

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Date:   Tue, 18 May 2021 09:37:12 +0800
From:   Johnny Chuang <johnny.chuang.emc@...il.com>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        Peter Hutterer <peter.hutterer@...-t.net>,
        linux-kernel@...r.kernel.org, linux-input@...r.kernel.org,
        Harry Cutts <hcutts@...omium.org>,
        Johnny Chuang <johnny.chuang@....com.tw>
Cc:     James Chen <james.chen@....com.tw>,
        Jennifer Tsai <jennifer.tsai@....com.tw>,
        Paul Liang <paul.liang@....com.tw>,
        Jeff Chuang <jeff.chuang@....com.tw>,
        Douglas Anderson <dianders@...omium.org>,
        Jingle <jingle.wu@....com.tw>, Paris Yeh <pyeh@...gle.com>,
        "sukumar . ghorai" <sukumar.ghorai@...el.corp-partner.google.com>
Subject: [PATCH v2] HID: i2c-hid: Add I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON to optimize timing

There is a hard coding 60ms delay after I2C_HID_PWR_ON commadn.
Elan didn't need the delay, so we add a quirk to reduce boot time and resume time.

Fixed: eef4016243e9("HID: i2c-hid: Always sleep 60ms after I2C_HID_PWR_ON commands")

Signed-off-by: Johnny Chuang <johnny.chuang.emc@...il.com>
---
Change in v2:
    - Modify Optimized tag to Fixed tag
    - Modify comment for i2c_hid_quirks
---
 drivers/hid/i2c-hid/i2c-hid-core.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 9993133..f4ee690 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -45,6 +45,7 @@
 #define I2C_HID_QUIRK_BOGUS_IRQ			BIT(4)
 #define I2C_HID_QUIRK_RESET_ON_RESUME		BIT(5)
 #define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(6)
+#define I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON	BIT(8)
 
 
 /* flags */
@@ -178,6 +179,11 @@ static const struct i2c_hid_quirks {
 		 I2C_HID_QUIRK_RESET_ON_RESUME },
 	{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
 		I2C_HID_QUIRK_BAD_INPUT_SIZE },
+	/*
+	 * Elan devices don't need delay after I2C_HID_PWR_ON
+	 */
+	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
+		 I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON },
 	{ 0, 0 }
 };
 
@@ -427,7 +433,8 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
 	 * PWR_ON requests. Testing has confirmed that several devices
 	 * will not work properly without a delay after a PWR_ON request.
 	 */
-	if (!ret && power_state == I2C_HID_PWR_ON)
+	if (!ret && power_state == I2C_HID_PWR_ON &&
+	    !(ihid->quirks & I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON))
 		msleep(60);
 
 	return ret;
-- 
2.7.4