Re: [PATCH] i2c: designware: Add disable runtime pm quirk

From: Jarkko Nikula
Date: Wed Jun 26 2019 - 02:27:31 EST

On 6/26/19 5:32 AM, AceLan Kao wrote:
Adding I2C_HID_QUIRK_NO_RUNTIME_PM quirk doesn't help on this issue.
Actually, Goodix touchpad already has that PM quirk in the list for other issue.
I also modify the code as you suggested, but no luck.

Yeah, I realized it won't help as the i2c-hid device is anyway powered on constantly when the device is open by the pm_runtime_get_sync() call in i2c_hid_open().

It's not Goodix takes time to wakeup, it's designware I2C controller.
Designware doesn't do anything wrong here, it's Goodix set the interrupt timeout
that leads to the issue, so we have to prevent designware from runtime
But only on that bus where Goodix is connected and open by user space.
What I mean something like below:

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 90164fed08d3..bbeaa39ddc23 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -795,6 +795,9 @@ static int i2c_hid_open(struct hid_device *hid)
struct i2c_hid *ihid = i2c_get_clientdata(client);
int ret = 0;

+ /* some quirk test here */
+ pm_runtime_get_sync(&client->adapter->dev);
ret = pm_runtime_get_sync(&client->dev);
if (ret < 0)
return ret;
@@ -812,6 +815,9 @@ static void i2c_hid_close(struct hid_device *hid)

/* Save some power */
+ /* some quirk test here */
+ pm_runtime_put(&client->adapter->dev);

static int i2c_hid_power(struct hid_device *hid, int lvl)