Hi all, I am sorry for the format mess up. Some messages are missing and just have an additional description here. Weida's controllers(WDT8752/WDT8755) require 2 steps to wakeup from SLEEP mode. The first command will wakeup the controller but will be ignored. The second command will be executed when the controller was active. Hn.chen. -----Original Message----- From: hn.chen@xxxxxxxxxxxxxxx [mailto:hn.chen@xxxxxxxxxxxxxxx] Sent: Monday, November 07, 2016 6:39 PM To: jkosina@xxxxxxx Cc: benjamin.tissoires@xxxxxxxxxx; dmitry.torokhov@xxxxxxxxx; linux-input@xxxxxxxxxxxxxxx; Hn Chen Subject: [PATCH] HID: i2c-hid: add retry in set power for fixing weida's issue From: HungNien Chen <hn.chen@xxxxxxxxxxxxxxx> Just modify the set_power function to send the command twice. It should be ok for other contorllers since it will jump out the loop after the first command send out. If this is not a proper modification, please tell me a proper way to fix this kind of issue. Signed-off-by: HungNien Chen <hn.chen@xxxxxxxxxxxxxxx> --- drivers/hid/i2c-hid/i2c-hid.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index b3ec4f2..d7423d9 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -49,6 +49,8 @@ #define I2C_HID_PWR_ON 0x00 #define I2C_HID_PWR_SLEEP 0x01 +#define SET_PWR_RETRIES 2 + /* debug option */ static bool debug; module_param(debug, bool, 0444); @@ -343,14 +345,26 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state) { struct i2c_hid *ihid = i2c_get_clientdata(client); int ret; + int retry; i2c_hid_dbg(ihid, "%s\n", __func__); - ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state, - 0, NULL, 0, NULL, 0); - if (ret) - dev_err(&client->dev, "failed to change power setting.\n"); + /* + * Some Weida's controllers require Set_Power twice on resume. + * The 1st cmd wakeup the controller and the 2nd cmd will be executed. + * It should be safe to controllers of other vendors. + */ + for (retry = 0; retry < SET_PWR_RETRIES; retry++) { + ret = __i2c_hid_command(client, &hid_set_power_cmd, + power_state, 0, NULL, 0, NULL, 0); + + if (!ret) + goto set_power_exit; + } + + dev_err(&client->dev, "failed to change power setting.\n"); +set_power_exit: return ret; } -- 1.9.1 ?頨{.n?????%??橆??w?{.n???{殺)暻蜋?^n?←屹??h?霅??輈蹂z嫡?+€?zfㄑ搬?坍??i????蔰_霈熝:+v??舝鷰
