The idea of this changes was inspired by discussion [1]. Now IRQ mappings are always created for all (allowed) GPIOs in GPIO irqchip in gpiochip_irqchip_add_key() and this goes against the idea of SPARSE_IRQ and, as result, leads to: - increasing of memory consumption because of allocated IRQ descriptors most of which will never ever be used (especially on platform with a high number of GPIOs). - imposibility to use GPIO irqchip APIs by gpio drivers when HW implements GPIO IRQ functionality as IRQ crossbar/multiplexer which has only limited number of IRQ outputs (example from [1], all GPIOs can be mapped on only 8 IRQs). Hence, remove static IRQ mapping code from gpiochip_irqchip_add_key() and instead replace irq_find_mapping() with irq_create_mapping() in gpiochip_to_irq(). Also add additional gpiochip_irqchip_irq_valid() calls in gpiochip_to_irq() and gpiochip_irq_map(). After this change gpio2irq mapping will happen the following way when GPIO irqchip APIs are used by gpio driver: - IRQ mappings will be created statically if driver passes first_irq>0 vlaue in gpiochip_irqchip_add_key(). - IRQ mappings will be created dynamically from gpio_to_irq() or of_irq_get(). Tested on am335x-evm and dra72-evm-revc. - dra72-evm-revc: number of created irq mappings decreased from 402 -> 135 - am335x-evm: number of created irq mappings decreased from 188 -> 63 It's good to have more testing feedbacks for these patches (personally I do not expect regressions, but who knows). One possible side effect is "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n" message during boot, but in this case it might be good to take a look on such GPIO drivers to understand why they need to allocate IRQ descriptors. [1] https://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1435847.html Grygorii Strashko (3): gpio: tegra: remove gpio_to_irq() from hw irq handlers gpio: pxa: remove gpio_to_irq() from hw irq handlers gpiolib: make gpio irqchip compatible with sparse_irq drivers/gpio/gpio-pxa.c | 8 +++++--- drivers/gpio/gpio-tegra.c | 3 ++- drivers/gpio/gpiolib.c | 29 ++++++----------------------- include/linux/gpio/driver.h | 1 - 4 files changed, 13 insertions(+), 28 deletions(-) -- 2.10.1 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
