Re: [PATCH] Revert "Input: atmel_mxt_ts - disable interrupt for 50ms after reset"

[Nick Dyer <nick.dyer@itdev.co.uk>]

On 2016-04-08 13:39, Tom Rini wrote:
>>>> I have a Pixel 2 here - can you advise how to reproduce?
>>>
>>> I (and a bunch of other folks, the linux-samus people now point people
>>> at using mxt-app every boot to reset the device) see this every time I
>>> either suspend the laptop or do a warm boot into a new kernel (I didn't
>>> try kexec but it too is probably broken).  Note that I'm not using
>>> mainline to boot ChromeOS but I've got a regular Linux distro in ROOT-C.
>>
>> OK. I will try it. My Pixel is running Ubuntu with a mainline kernel, so
>> should be able to repro.
> 
> Thanks.  Happy to test patches when you get there and feel free to shoot
> me patches to have more info get dumped out or whatever if needed.

Could you try the below patch to correctly acquire the IRQ after soft reset on
systems using IRQF_TRIGGER_FALLING.

Appears to work correctly on my Pixel 2 during a brief test.

A workaround also seems to be to reconfig T18 COMMSCONFIG to enable
the RETRIGEN bit using mxt-app:
    mxt-app -W -T18 44
    mxt-app --backup
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2160512e..5af7907 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -1093,6 +1093,19 @@ static int mxt_t6_command(struct mxt_data *data, u16 cmd_offset,
 	return 0;
 }
 
+static int mxt_acquire_irq(struct mxt_data *data)
+{
+	int error;
+
+	enable_irq(data->irq);
+
+	error = mxt_process_messages_until_invalid(data);
+	if (error)
+		return error;
+
+	return 0;
+}
+
 static int mxt_soft_reset(struct mxt_data *data)
 {
 	struct device *dev = &data->client->dev;
@@ -1111,7 +1124,7 @@ static int mxt_soft_reset(struct mxt_data *data)
 	/* Ignore CHG line for 100ms after reset */
 	msleep(100);
 
-	enable_irq(data->irq);
+	mxt_acquire_irq(data);
 
 	ret = mxt_wait_for_completion(data, &data->reset_completion,
 				      MXT_RESET_TIMEOUT);
@@ -1466,19 +1479,6 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *cfg)
 	return ret;
 }
 
-static int mxt_acquire_irq(struct mxt_data *data)
-{
-	int error;
-
-	enable_irq(data->irq);
-
-	error = mxt_process_messages_until_invalid(data);
-	if (error)
-		return error;
-
-	return 0;
-}
-
 static int mxt_get_info(struct mxt_data *data)
 {
 	struct i2c_client *client = data->client;