Re: [PATCH v1] Input: touchscreen: ads7846.c: fix integer overflow on Rt calculation

[Dmitry Torokhov]

On Fri, Nov 13, 2020 at 12:22:40PM +0100, Oleksij Rempel wrote:
> In some rare cases the 32 bit Rt value will overflow if z2 and x is max,
> z1 is minimal value and x_plate_ohms is relatively high (for example 800
> ohm). This would happen on some screen age with low pressure.
> 
> There are two possible fixes:
> - make Rt 64bit
> - reorder calculation to avoid overflow
> 
> The second variant seems to be preferable, since 64 bit calculation on
> 32 bit system is a bit more expensive.
> 
> Fixes: ffa458c1bd9b6f653008d450f337602f3d52a646 ("spi: ads7846 driver")
> Co-Developed-by: David Jander <david@xxxxxxxxxxx>
> Signed-off-by: David Jander <david@xxxxxxxxxxx>
> Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>

Applied, thank you.

-- 
Dmitry