Thread (3 messages) 3 messages, 3 authors, 2021-05-18

Re: [PATCH] HID: i2c-hid: Add I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON to optimize timing

From: Harry Cutts <hidden>
Date: 2021-05-18 00:15:53
Also in: lkml

On Mon, 17 May 2021 at 16:57, Johnny Chuang [off-list ref] wrote:
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.

Optimized: eef4016243e9("HID: i2c-hid: Always sleep 60ms after I2C_HID_PWR_ON commands")
I don't think Optimized: is a valid commit tag, though I'm not sure if
it'll cause any problems.
quoted hunk ↗ jump to hunk
Signed-off-by: Johnny Chuang <redacted>
---
 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..e7ec280 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
[...snip...]
@@ -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 },
+       /*
+        * Optimize boot time and resume time
+        */
This comment is a bit too vague to be useful; maybe state that Elan
devices don't need the delay instead, or just remove the comment.

Other than that,

Reviewed-by: Harry Cutts <redacted>
quoted hunk ↗ jump to hunk
+       { 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
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