On Mon, May 10, 2021 at 7:39 PM Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > > On Mon, May 10, 2021 at 11:29:08AM +0200, Linus Walleij wrote: > > On Mon, May 10, 2021 at 2:22 AM Dmitry Torokhov > > <dmitry.torokhov@xxxxxxxxx> wrote: > > > On Mon, May 10, 2021 at 01:38:30AM +0200, Linus Walleij wrote: > > > > > > This edge setting should come from the device tree not > > > > the driver. Also, most device trees sets this to the > > > > falling edge, which is contradictory to what is hardcoded. > > > > > > I see there are 2 possibilities: > > > > > > 1. The driver has never worked > > > 2. DT interrupt annotation is wrong. > > > > > > It would be nice to know if we are dealing with 1 or 2, as in case of #2 > > > we need to adjust DTSes before this patch can be applied. > > > > I looked closer and unfortunately the mess and confusion > > is bizarre. > > > > The DTS files we know of are: > > arch/arm/boot/dts/am3517-som.dtsi - rising > > arch/arm/boot/dts/imx28-tx28.dts - falling > > arch/arm/boot/dts/imx35-eukrea-cpuimx35.dtsi - low > > arch/arm/boot/dts/imx51-eukrea-cpuimx51.dtsi - low > > arch/arm/boot/dts/imx53-tx53-x03x.dts - falling > > arch/arm/boot/dts/imx6q-dhcom-som.dtsi - falling > > arch/arm/boot/dts/imx6qdl-tx6.dtsi - none > > arch/arm/boot/dts/imx6ul-tx6ul.dtsi - none > > arch/arm/boot/dts/imx7d-nitrogen7.dts - falling > > arch/arm/boot/dts/logicpd-som-lv.dtsi - rising > > arch/arm/boot/dts/logicpd-torpedo-baseboard.dtsi - rising > > arch/arm/boot/dts/omap3-gta04.dtsi - falling > > arch/arm/boot/dts/omap3-n900.dts - rising > > arch/arm/boot/dts/omap4-var-som-om44.dtsi - low > > arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi - falling > > > > We can assume that some of this is the result of board > > engineers introducing inverters on the board as is custom, > > so the flags are actually correct when set to falling, just > > that we don't model the inverter. > > > > In the case of imx6qdl-tx6 and imx6ul-tx6ul with "none" IRQ > > type I assume this flag in the driver is actually necessary > > for the device to work at all. > > > > In the cases where rising is set, the addition of the flag is > > plain tautology, just setting what is already set. > > > > In the cases where falling are set the interrupts will arrive > > on both edges (if the hardware can provide that, which is > > not always the case) and as a result fire twice as many > > interrupts as they should, probably with zero effect on the > > second IRQ, just reporting nothing. > > That is not how we set up interrupts though. We only use > platform-supplied trigger if caller did not specify trigger when calling > request_irq(). From kernel/irq/manage.c::__setup_irq(): > > /* > * If the trigger type is not specified by the caller, > * then use the default for this interrupt. > */ > if (!(new->flags & IRQF_TRIGGER_MASK)) > new->flags |= irqd_get_trigger_type(&desc->irq_data); > > So in our case, since driver specified IRQF_TRIGGER_RISING it is how > interrupt line was configured, and what was in DTS had no effect. > > > > > The combination with active low is weird. I wonder what > > happens there. > > > > I am just confused now and have no idea what to do about > > it... > > > > But I just CC all the Freescale and OMAP people who > > seem to maintain these DTS files so they can clarify > > how well assigned these edges, none and active low (!) > > IRQs are. > > Hopefully they can confirm how the controller is wired on their boards > and then we can correct invalid DTSes and then finally apply your patch > to the driver. I reviewed the Logicpd Torpedo (DM3730) and there isn't an interter. I changed the device tree entry for it to falling edge instead and rising, and it continued to work perfectly. I'll review both the schematics and test the am3517-evm and the logicpd som-lv, but I am going to expect the same results since they'll all basically copy-paste of each other. Once I've completed my analysis, I'll post device tree updates for all the logicpd stuff. adam > > Thanks. > > -- > Dmitry
