diff mbox

Input: atmel_mxt_ts - use mxt_acquire_irq in mxt_soft_reset

Message ID 1460367105-29258-1-git-send-email-nick.dyer@itdev.co.uk (mailing list archive)
State Accepted
Headers show

Commit Message

Nick Dyer April 11, 2016, 9:31 a.m. UTC
If using IRQF_TRIGGER_FALLING, then there is a race here: if the reset
completes before we enable the IRQ, then CHG is already low and touch
will be broken.

This has been seen on Chromebook Pixel 2.

A workaround is to reconfig T18 COMMSCONFIG to enable the RETRIGEN bit
using mxt-app:
    mxt-app -W -T18 44
    mxt-app --backup

Tested-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Comments

Dmitry Torokhov April 25, 2016, 9:28 p.m. UTC | #1
On Mon, Apr 11, 2016 at 10:31:45AM +0100, Nick Dyer wrote:
> If using IRQF_TRIGGER_FALLING, then there is a race here: if the reset
> completes before we enable the IRQ, then CHG is already low and touch
> will be broken.
> 
> This has been seen on Chromebook Pixel 2.
> 
> A workaround is to reconfig T18 COMMSCONFIG to enable the RETRIGEN bit
> using mxt-app:
>     mxt-app -W -T18 44
>     mxt-app --backup
> 
> Tested-by: Tom Rini <trini@konsulko.com>
> Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>

Applied, thank you.

> ---
>  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 2160512..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 @@ release_mem:
>  	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;
> -- 
> 2.5.0
>
diff mbox

Patch

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2160512..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 @@  release_mem:
 	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;