On Mon, Nov 4, 2019 at 3:43 PM Sven Van Asbroeck <thesven73@xxxxxxxxx> wrote: > > Hi Adam, > > On Mon, Nov 4, 2019 at 4:28 PM Adam Ford <aford173@xxxxxxxxx> wrote: > > > > I am using IRQ_TYPE_EDGE_RISING for the 2117A. Is that correct? For > > my touchscreen, the IRQ line is low until a touch is detected, so I > > assume we want to capure on the rising edge. > > That is correct for the 2117A, as far as I know. I am using the same > setting. > > > > > Regarding Dmitry's patch, > > Is it a good idea to use msleep in an IRQ? It seems like using the > > schedule_delayed_work() call seems like it will get in and get out of > > the ISR faster. > > > > If we use msleep and scan again, isn't it possible to starve other processes? > > I believe using msleep() is ok because this is not a "real" interrupt handler, > but a threaded one. It runs in a regular kernel thread, with its interrupt > turned off (but all other interrupts remain enabled). Its interrupt is > re-enabled automatically after the threaded handler returns. > > See > https://elixir.bootlin.com/linux/latest/source/include/linux/interrupt.h#L50 > > > > @@ -268,7 +278,7 @@ static irqreturn_t ili210x_irq(int irq, void *irq_data) > > > } > > > > > > touch = ili210x_report_events(priv, touchdata); > > > - keep_polling = touch || chip->continue_polling(touchdata); > > > + keep_polling = chip->continue_polling(touchdata, touch); > > > if (keep_polling) > > > > Why not just check the value of touch instead of invoking the function > > pointer which takes the value of touch in as a parameter? > > > > The value of touch must be checked inside the callback, because > some variants use it to decide if they should poll again, and > some do not, such as the ili211x. That makes sense. > > If I have misinterpreted your suggestion, could you perhaps > express it in C, so I can understand better? You explained it. I'm good. adam
