From: Hamish Martin Date: Wed, 25 Oct 2023 03:55:11 +0000 (+1300) Subject: HID: mcp2221: Allow IO to start during probe X-Git-Tag: v6.6.17~1911 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d4b50ac06ea6e47bdd2b04e97d1090c673c80645;p=platform%2Fkernel%2Flinux-rpi.git HID: mcp2221: Allow IO to start during probe [ Upstream commit 73ce9f1f2741a38f5d27393e627702ae2c46e6f2 ] During the probe we add an I2C adapter and as soon as we add that adapter it may be used for a transfer (e.g via the code in i2cdetect()). Those transfers are not able to complete and time out. This is because the HID raw_event callback (mcp2221_raw_event) will not be invoked until the HID device's 'driver_input_lock' is marked up at the completion of the probe in hid_device_probe(). This starves the driver of the responses it is waiting for. In order to allow the I2C transfers to complete while we are still in the probe, start the IO once we have completed init of the HID device. This issue seems to have been seen before and a patch was submitted but it seems it was never accepted. See: https://lore.kernel.org/all/20221103222714.21566-3-Enrik.Berkhan@inka.de/ Signed-off-by: Hamish Martin Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c index b95f31c..aef0785 100644 --- a/drivers/hid/hid-mcp2221.c +++ b/drivers/hid/hid-mcp2221.c @@ -1142,6 +1142,8 @@ static int mcp2221_probe(struct hid_device *hdev, if (ret) return ret; + hid_device_io_start(hdev); + /* Set I2C bus clock diviser */ if (i2c_clk_freq > 400) i2c_clk_freq = 400;