On Friday 01 April 2016 13:44:08, Linus Walleij wrote: > The gpiolib does not currently return probe deferrals from the > .to_irq() hook while the GPIO drivers are being initialized. > Further: it keeps returning -EPROBE_DEFER for gpio[d]_get() > even after all builtin drivers have initialized. > > Fix this thusly: > > - Move the assignment of .to_irq() to the last step when > using gpiolib_irqchip_add() so we can't get spurious calls > into the .to_irq() function until all set-up is finished. > > - Put in a late_initcall_sync() to set a boolean state variable to > indicate that we're not gonna defer any longer. Since deferred > probe happens at late_initcall() time, using late_initcall_sync() > should be fine. > > - After this point, return hard errors (-ENXIO) from both > gpio[d]_get() and .to_irq(). > > This way we should (at least for all drivers using GPIOLIB_IRQCHIP) > be getting proper deferrals from both gpio[d]_get() and .to_irq() > until the irqchip side is properly set up, and then proper > errors after all drivers should have been probed. > > This problem was first seen with gpio-keys. > > Cc: linux-input@xxxxxxxxxxxxxxx > Cc: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> > Cc: Guenter Roeck <linux@xxxxxxxxxxxx> > Reported-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > --- > Alexander: please test this, you need Guether's patches too, > I have it all on my "fixes" branch in the GPIO git: > https://git.kernel.org/cgit/linux/kernel/git/linusw/linux-gpio.git/log/?h=fi > xes I cherry-picked the top most 3 patches: 7f41f039a096a957eaa3e0ef0b040d96e7ad200d 2f126cda38e0614b3e8d211047b18e831b110f82 e6918cd02fd84402311f3fab4b218d9c911e70d6 Unfortunately it does not fix it. At least I do not get an IRQ of 0. After 10 boots: 4x gpio-keys user_sw: Unable to get irq number for GPIO 376, error -6 1x gpio-keys dip: Unable to get irq number for GPIO 352, error -6 5x ok user_sw and dip are essientially the same, just different devices in DT with different gpiochip parents (MCP23S18 and PCA9555). I noticed you fiddle with late_initcall_sync. Sorry, I did not mention it: gpio_mcp23s08 as well as gpio_keys are loaded as modules, so late_initcall_* should not affect it. Best regards, Alexander -- 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
