[v1] Input: elants_i2c - fix division by zero if firmware reports zero phys size
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Message ID 20210302100824.3423-1-digetx@gmail.com
State New, archived
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  • [v1] Input: elants_i2c - fix division by zero if firmware reports zero phys size
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Commit Message

Dmitry Osipenko March 2, 2021, 10:08 a.m. UTC
Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
size. Hence check whether the size is zero and don't set the resolution in
this case.

Reported-by: Jasper Korten <jja2000@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---

Please note that ASUS TF700T isn't yet supported by upstream kernel,
hence this is not a critical fix.

 drivers/input/touchscreen/elants_i2c.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Michał Mirosław March 3, 2021, 11:19 p.m. UTC | #1
On Tue, Mar 02, 2021 at 01:08:24PM +0300, Dmitry Osipenko wrote:
> Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
> size. Hence check whether the size is zero and don't set the resolution in
> this case.
> 
> Reported-by: Jasper Korten <jja2000@gmail.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---

Rewieved-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>


> Please note that ASUS TF700T isn't yet supported by upstream kernel,
> hence this is not a critical fix.
> 
>  drivers/input/touchscreen/elants_i2c.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
> index 4c2b579f6c8b..a2e1cc4192b0 100644
> --- a/drivers/input/touchscreen/elants_i2c.c
> +++ b/drivers/input/touchscreen/elants_i2c.c
> @@ -1441,14 +1441,16 @@ static int elants_i2c_probe(struct i2c_client *client,
>  
>  	touchscreen_parse_properties(ts->input, true, &ts->prop);
>  
> -	if (ts->chip_id == EKTF3624) {
> +	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
>  		/* calculate resolution from size */
>  		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
>  		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
>  	}
>  
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
> +	if (ts->x_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> +	if (ts->y_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);

I would guess that you can tie X and Y in one if, as they are unlikely
to work independently.

Best Regards
Michal Mirosław
Dmitry Osipenko March 26, 2021, 1:24 p.m. UTC | #2
02.03.2021 13:08, Dmitry Osipenko пишет:
> Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
> size. Hence check whether the size is zero and don't set the resolution in
> this case.
> 
> Reported-by: Jasper Korten <jja2000@gmail.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> 
> Please note that ASUS TF700T isn't yet supported by upstream kernel,
> hence this is not a critical fix.
> 
>  drivers/input/touchscreen/elants_i2c.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
> index 4c2b579f6c8b..a2e1cc4192b0 100644
> --- a/drivers/input/touchscreen/elants_i2c.c
> +++ b/drivers/input/touchscreen/elants_i2c.c
> @@ -1441,14 +1441,16 @@ static int elants_i2c_probe(struct i2c_client *client,
>  
>  	touchscreen_parse_properties(ts->input, true, &ts->prop);
>  
> -	if (ts->chip_id == EKTF3624) {
> +	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
>  		/* calculate resolution from size */
>  		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
>  		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
>  	}
>  
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
> +	if (ts->x_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> +	if (ts->y_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
>  	if (ts->major_res > 0)
>  		input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, ts->major_res);
>  
> 

Hi,

This is a very minor fix, but still will be nice if we could get it into
5.13 in order to have one less patch to care about. Thanks in advance!
Dmitry Torokhov March 28, 2021, 4:44 a.m. UTC | #3
Hi Dmitry,

On Tue, Mar 02, 2021 at 01:08:24PM +0300, Dmitry Osipenko wrote:
> Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
> size. Hence check whether the size is zero and don't set the resolution in
> this case.
> 
> Reported-by: Jasper Korten <jja2000@gmail.com>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> 
> Please note that ASUS TF700T isn't yet supported by upstream kernel,
> hence this is not a critical fix.
> 
>  drivers/input/touchscreen/elants_i2c.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
> index 4c2b579f6c8b..a2e1cc4192b0 100644
> --- a/drivers/input/touchscreen/elants_i2c.c
> +++ b/drivers/input/touchscreen/elants_i2c.c
> @@ -1441,14 +1441,16 @@ static int elants_i2c_probe(struct i2c_client *client,
>  
>  	touchscreen_parse_properties(ts->input, true, &ts->prop);
>  
> -	if (ts->chip_id == EKTF3624) {
> +	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
>  		/* calculate resolution from size */
>  		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
>  		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
>  	}
>  
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> -	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
> +	if (ts->x_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);

There is absolutely no difference between setting respluton to 0 vs not
setting it at all, so I dropped the conditionals and applied.

> +	if (ts->y_res > 0)
> +		input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
>  	if (ts->major_res > 0)

We could drop this condition as well.

>  		input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, ts->major_res);
>  
> -- 
> 2.29.2
> 

Thanks.
Dmitry Osipenko March 28, 2021, 5:21 p.m. UTC | #4
28.03.2021 07:44, Dmitry Torokhov пишет:
> Hi Dmitry,
> 
> On Tue, Mar 02, 2021 at 01:08:24PM +0300, Dmitry Osipenko wrote:
>> Touchscreen firmware of ASUS Transformer TF700T reports zeros for the phys
>> size. Hence check whether the size is zero and don't set the resolution in
>> this case.
>>
>> Reported-by: Jasper Korten <jja2000@gmail.com>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>>
>> Please note that ASUS TF700T isn't yet supported by upstream kernel,
>> hence this is not a critical fix.
>>
>>  drivers/input/touchscreen/elants_i2c.c | 8 +++++---
>>  1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
>> index 4c2b579f6c8b..a2e1cc4192b0 100644
>> --- a/drivers/input/touchscreen/elants_i2c.c
>> +++ b/drivers/input/touchscreen/elants_i2c.c
>> @@ -1441,14 +1441,16 @@ static int elants_i2c_probe(struct i2c_client *client,
>>  
>>  	touchscreen_parse_properties(ts->input, true, &ts->prop);
>>  
>> -	if (ts->chip_id == EKTF3624) {
>> +	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
>>  		/* calculate resolution from size */
>>  		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
>>  		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
>>  	}
>>  
>> -	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
>> -	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
>> +	if (ts->x_res > 0)
>> +		input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
> 
> There is absolutely no difference between setting respluton to 0 vs not
> setting it at all, so I dropped the conditionals and applied.
> 
>> +	if (ts->y_res > 0)
>> +		input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
>>  	if (ts->major_res > 0)
> 
> We could drop this condition as well.
> 
>>  		input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, ts->major_res);

I'll make a follow up patch to clean up this condition, if you haven't
done it yet. Thanks!

Patch
diff mbox series

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index 4c2b579f6c8b..a2e1cc4192b0 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -1441,14 +1441,16 @@  static int elants_i2c_probe(struct i2c_client *client,
 
 	touchscreen_parse_properties(ts->input, true, &ts->prop);
 
-	if (ts->chip_id == EKTF3624) {
+	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
 		/* calculate resolution from size */
 		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
 		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
 	}
 
-	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
-	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
+	if (ts->x_res > 0)
+		input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
+	if (ts->y_res > 0)
+		input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
 	if (ts->major_res > 0)
 		input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, ts->major_res);