From mboxrd@z Thu Jan 1 00:00:00 1970 From: maitysanchayan@gmail.com (maitysanchayan at gmail.com) Date: Mon, 14 Dec 2015 13:23:39 +0530 Subject: touchscreen: edt-ft5x06: Prevent DMA driver from mapping an area on stack In-Reply-To: <20151213044237.GA22780@dtor-ws> References: <20151212171355.GA7362@katana> <20151213044237.GA22780@dtor-ws> Message-ID: <20151214075339.GA28733@Sanchayan-Arch.toradex.int> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On 15-12-12 20:42:37, Dmitry Torokhov wrote: > On Sat, Dec 12, 2015 at 06:13:55PM +0100, Wolfram Sang wrote: > > > > > 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.