Re: touchscreen: edt-ft5x06: Prevent DMA driver from mapping an area on stack

Hello,

On 15-12-12 20:42:37, Dmitry Torokhov wrote:

On Sat, Dec 12, 2015 at 06:13:55PM +0100, Wolfram Sang wrote:

quoted

quoted

Frankly speaking I do not know where the fix should actually be. I2C IMX
driver somehow taking care of this or the users of I2C, touchscreen drivers
in this case. In my opinion, the fix should be with the touchscreen driver
however I did like to have feedback or hear opinions on what is the accepted
solution to this.

There is no accepted solution to this yet :( DMA is/was still too rare for
a serious discussion about this. There is also [1] and probably more...

[1]  http://patchwork.ozlabs.org/patch/220137/

I believe vast majority of i2c client drivers do not expect that the
transfer buffer they supply in i2c messages are supposed to be DMAable
(unlike USB and SPI buses that had that requirement from the beginning).

I won't be applying this patch unless we decide that I2C changes the
rules.

Understood. Thanks for the clarifications Dmitry and Wolfram.

- Sanchayan.