Takashi Iwai wrote:
Clemens Ladisch wrote:
ALSA: mpu401: clean up interrupt specification
The semantics of snd_mpu401_uart_new()'s interrupt parameters are somewhat counterintuitive: To prevent the function from allocating its own interrupt, either the irq number must be invalid, or the irq_flags parameter must be zero. At the same time, the irq parameter being invalid specifies that the mpu401 code has to work without an interrupt allocated by the caller. This implies that, if there is an interrupt and it is allocated by the caller, the irq parameter must be set to a valid-looking number which then isn't actually used.
With the removal of IRQF_DISABLED, zero becomes a valid irq_flags value, which forces us to handle the parameters differently.
This patch introduces a new flag MPU401_INFO_IRQ_HOOK for when the device interrupt is handled by the caller, and makes the allocation of the interrupt to depend only on the irq parameter.
Signed-off-by: Clemens Ladisch clemens@ladisch.de
This patch looks better indeed.
However, if we are going to remove IRQF_DISABLED in near future, and all the callers use IRQF_DISABLED when requesting an irq, why not remove this argument now? Then the IRQF_DISABLED-removal patch will touch less code.
I wanted to change only the minimum amount of code needed to make the IRQF_DISABLED-removal patch possible, and wait with further cleanups of snd_mpu401_uart_new() until after that patch to avoid conflicts.
However, moving the IRQF_DISABLED into snd_mpu401_uart_new() avoids those conflicts, so it's clearly better.
Regards, Clemens