On Tue, Jul 26, 2016 at 6:13 PM, Marcos Souza <marcos.souza.org@xxxxxxxxx> wrote: > Hi Dmitry, > > On Mon, Jul 25, 2016 at 3:48 PM, Marcos Souza > <marcos.souza.org@xxxxxxxxx> wrote: >> Hi Dmitry, >> >> On Mon, Jul 25, 2016 at 3:22 PM Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> >> wrote: >>> >>> [ resending to all - mutt is for some reason confused about recipent >>> list ] >>> On Mon, Jul 25, 2016 at 02:20:16PM -0300, Marcos Paulo de Souza wrote: >>> > On suspend/resume cycle, selftest is executed on to reset i8042 >>> > controller. But >>> > when this is done in these devices, posterior calls to detect/init >>> > functions >>> > to elantech driver fails. Skipping selftest fixes this problem. >>> > >>> > An easier step to reproduce this problem is adding i8042.reset=1 as a >>> > kernel >>> > parameter. On problematic laptops, it'll make the system to start with >>> > the >>> > touchpad already stucked, since psmouse_probe forcibly calls the >>> > selftest function. >>> > >>> > This patch was inspired by John Hiesey's change[1]. >>> > >>> > [1]: https://marc.info/?l=linux-input&m=144312209020616&w=2 >>> > >>> > Fixes: "ETPS/2 Elantech Touchpad dies after resume from suspend" >>> > (https://bugzilla.kernel.org/show_bug.cgi?id=7739) >>> >>> *sigh* You just cant win, they'll manage to mess up the firmware one way >>> or another :( Witness: >> >> >> They're experts on messing things up :( >> >>> >>> >>> " >>> commit 1ca56e513a9fd356d5a9e0de45dbe0e189e00386 >>> Author: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> >>> Date: Tue Jul 20 20:25:34 2010 -0700 >>> >>> Input: i8042 - reset keyboard controller wehen resuming from S2R >>> >>> Some laptops, such as Lenovo 3000 N100, require keyboard controller >>> reset >>> in order to have touchpad operable after suspend to RAM. Even if box >>> does >>> not need the reset it should be safe to do so, so instead of chasing >>> after misbehaving boxes and grow DMI tables, let's reset the >>> controller >>> unconditionally. >>> >>> Reported-and-tested-by: Jerome Lacoste <jerome.lacoste@xxxxxxxxx> >>> Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx> >>> " >>> >>> so apparently it is not safe to reset the controller on resume. Oh joy. >>> >>> The issue I have here is selftest is the same as reset, and we already >>> have i8042_reset flag, so 2 flags controlling the same functionality is >>> not great. Could we extend i8042 to an enum, like: >>> >>> I8042_RESET_ALWAYS >>> I8042_RESET_NEVER >>> I8042_RESET_ON_RESUME (default) >>> >>> and have a custom module parameter for it? >>> >>> i8042.reset and i8042_reset={1|Y|y} would result in I8042_RESET_ALWAYS >>> i8042.reset={0|N|n} would result in I8042_RESET_NEVER >>> Without i8042.reset we just reset it when resuming from S3. >>> >>> What do you think? >> >> >> Seems to be a very good approach. I'll send a new version. > > You asked me to adapt my previous patch, making it accept: > > i8042.reset > i8042.reset={1,y,Y} > i8042.reset={0,n,N} > > But, when using a charp as module parameter, it doesn't allocate > memory to i8042_reset when we don't use the equal sign. So, in this > case I can't tell if the user is using i8042.reset, or don't any > parameter (in this case it means to use I8042_RESET_ON_RESUME) > > So, in this case, should we just change i8042.reset to accept 1,y,n? > This should solve the problem too (although I think people who already > use such parameter will complain...) > > What do you think? I think you will have to provide custom parameter parsing method. psmouse module has one, so you can use it as an example. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
